Style: Add anchor links to all subheads

* Adds Makefile test to ensure all subheadings, except those on Choose
  Your Wallet, have an ID (anchor reference)

* Adds an ID to all subheads that didn't have on previously

Makefile

@@ -41,7 +41,8 @@ pre-build-tests-fast: check-for-non-ascii-urls check-for-wrong-filename-assignme
 post-build-tests-fast: check-for-build-errors ensure-each-svg-has-a-png check-for-liquid-errors \
     check-for-missing-anchors check-for-broken-markdown-reference-links \
     check-for-broken-kramdown-tables check-for-duplicate-header-ids \
-    check-for-headers-containing-auto-link check-for-missing-subhead-links
+    check-for-headers-containing-auto-link check-for-missing-subhead-links \
+    check-for-subheading-anchors
 
 ## All pre-build tests, including those which might take multiple minutes
 pre-build-tests: pre-build-tests-fast
@@ -214,3 +215,11 @@ check-html-proofer:
 
 travis-background-keepalive:
 	$S { while ps aux | grep -q '[m]ake' ; do echo "Ignore me: Travis CI keep alive" ; sleep 1m ; done ; } &
+
+check-for-subheading-anchors:
+## Ensure all subheadings on the site have anchors so the Javascript
+## function addAnchorLinks() can add anchor link affordance to each
+## subhead
+	$S grep -r -L 'Note: this file exempt from check-for-subheading-anchors check' _site/ \
+	  | xargs grep '<h[23456]' \
+	  | grep -v '<h[23456][^>]* id=' | eval $(ERROR_ON_OUTPUT)

_alerts/2012-03-16-critical-vulnerability.html

@@ -30,7 +30,7 @@
 0.5.3.1 for Windows and 0.5.3 for Linux</a>
 </p>
 
-<h3>Español: Vulnerabilidad de seguridad (potencialmente crítica)</h3>
+<h3 id="spanish">Español: Vulnerabilidad de seguridad (potencialmente crítica)</h3>
 <p>
 Una vulnerabilidad de seguridad posible no son afectadas en la versión Windows de Bitcoin-Qt. Si está utilizando Bitcoin-Qt 0.5 a través de las versiones 0.6 en Windows, debe cerrar y actualizar a la versión 0.5.3.1 o 0.6rc4 AHORA.
 </p><p>
@@ -49,7 +49,7 @@ <h3>Español: Vulnerabilidad de seguridad (potencialmente crítica)</h3>
 0.5.3.1 para Windows y 0.5.3 para Linux</a>
 </p>
 
-<h3>Deutsch: DRINGEND: Windows Bitcoin-Qt update</h3>
+<h3 id="german">Deutsch: DRINGEND: Windows Bitcoin-Qt update</h3>
 <p>
 Es wurde eine potenzielle Schwachstelle in der Windowsversion Qt-Bitcoin entdeckt. Wenn Sie mit Bitcoin-Qt-Versionen 0.5 bis 0.6 unter Windows arbeiten, sollten Sie das Programm beenden und ein Upgrade auf entweder Version 0.5.3.1 oder 0.6rc4 JETZT durchführen.
 </p><p>
@@ -70,7 +70,7 @@ <h3>Deutsch: DRINGEND: Windows Bitcoin-Qt update</h3>
 0.5.3.1 für Windows und 0.5.3 für Linux</a>
 </p>
 
-<h3>Nederlands: Mogelijk kritisch veiligheidsprobleem</h3>
+<h3 id="dutch">Nederlands: Mogelijk kritisch veiligheidsprobleem</h3>
 <p>
 Er is een een mogelijk veiligheidsprobleem gevonden in de Windows versie van
 Bitcoin-Qt. Als u Bitcoin-Qt versie 0.5 tot 0.6 draait, sluit het dan af
@@ -97,7 +97,7 @@ <h3>Nederlands: Mogelijk kritisch veiligheidsprobleem</h3>
 0.5.3.1 voor Windows en 0.5.3 for Linux</a>
 </p>
 
-<h3>Русский: Найдена потенциальная критическая уязвимость в версиях Bitcoin-Qt от 0.5 до 0.6 для Windows</h3>
+<h3 id="russian">Русский: Найдена потенциальная критическая уязвимость в версиях Bitcoin-Qt от 0.5 до 0.6 для Windows</h3>
 <p>
 Найдена потенциальная критическая уязвимость в версиях Bitcoin-Qt от 0.5 до 0.6 для Windows. Если вы используете одну из этих версий, отключите её и обновитесь до 0.5.3.1 или 0.6rc4 немедленно.
 </p><p>
@@ -117,7 +117,7 @@ <h3>Русский: Найдена потенциальная критическ
 0.5.3.1</a>
 </p>
 
-<h3>Italiano: Potenziale vulnerabilità di sicurezza critica.</h3>
+<h3 id="italian">Italiano: Potenziale vulnerabilità di sicurezza critica.</h3>
 <p>
 Una potenziale vulnerabilità di sicurezza è stata scoperta nella versione di Windows di Bitcoin-Qt. Se stai usando Bitcoin-Qt su Windows dalle versioni 0.5 alla 0.6 dovresti chiuderla e aggiornarla alle versioni 0.5.3.1 o 0.6rc4 ORA.
 </p><p>
@@ -134,7 +134,7 @@ <h3>Italiano: Potenziale vulnerabilità di sicurezza critica.</h3>
 0.5.3.2 per Windows e 0.5.3 per Linux</a>
 </p>
 
-<h3>Português: Vulnerabilidade de segurança potencialmente crítica</h3>
+<h3 id="portugese">Português: Vulnerabilidade de segurança potencialmente crítica</h3>
 <p>
 Uma vulnerabilidade de segurança em potencial foi descoberto na versão do Bitcoin-Qt para Windows. Se você estiver executando alguma versão entre a 0.5 até a 0.6 do Bitcoin-Qt no Windows, você deve desligá-lo e atualizá-lo para a versão 0.5.3.1 ou 0.6rc4 AGORA!
 </p><p>
@@ -155,7 +155,7 @@ <h3>Português: Vulnerabilidade de segurança potencialmente crítica</h3>
 Traduzido por Thiago Martins (ThiagoCMC)
 </p>
 
-<h3>Polski: Potencjalnie Krytyczne Zagrozenie Bezpieczenstwa</h3>
+<h3 id="polish">Polski: Potencjalnie Krytyczne Zagrozenie Bezpieczenstwa</h3>
 <p>
 Potencjalne zagrozenie zostalo odkryte w Bitcoin-QT wersji Windows. Jesli masz uruchomiony Bitcoin-Qt w wersjach 0.5 przez 0.6 w wersji Windows powinienes je zamknac i pobrac najnowsze wersje 0.5.3.1 lub 0.6rc4 TERAZ.
 </p><p>
@@ -174,7 +174,7 @@ <h3>Polski: Potencjalnie Krytyczne Zagrozenie Bezpieczenstwa</h3>
 0.5.3.1 dla WIndows  i 0.5.3 dla Linuxa</a>
 </p>
 
-<h3>Български език: Уязвимост в сигурността.</h3>
+<h3 id="bulgarian">Български език: Уязвимост в сигурността.</h3>
 <p>
 Уязвимост в сигурността бе открита при Windows версията на Bitcoin-Qt.Ако използвате Bitcoin-Qt версия 0.5 до 0.6 през Windows,ще се наложи да я спрете и да направите ъпгрейд  до 0.5.3.1 или 0.rc4.Command-line даемон-а(bitcoind),няма да бъде афектиран за потребители на Mac или Linux.Поради вида на тази уязвимост,ние вярваме,че би могло да бъде доста трудно за атакуващия да направи нещо повече от това да crash-не  процесът - Bitcoin-Qt.Поради това ние го считаме за критичен проблем.
 </p><p>
@@ -190,7 +190,7 @@ <h3>Български език: Уязвимост в сигурността.</
 0.5.3.1 за Windows и 0.5.3 за Linux.</a>
 </p>
 
-<h3>Ελληνικά: Σοβαρό πρόβλημα ασφάλειας</h3>
+<h3 id="greek">Ελληνικά: Σοβαρό πρόβλημα ασφάλειας</h3>
 <p>
 Ένα πιθανά σοβαρό πρόβλημα ασφάλειας εντοπίστηκε στην έκδοση Windows του Bitcoin-Qt. Εαν χρησιμοποιείτε Bitcoin-Qt εκδόσεις 0.5 έως 0.6 στα Windows, αναβαθμήστε <b>άμεσα</b> σε έκδοση 0.5.3.1 ή 0.6rc4.
 </p><p>
@@ -208,7 +208,7 @@ <h3>Ελληνικά: Σοβαρό πρόβλημα ασφάλειας</h3>
 0.5.3.1 για Windows και 0.5.3 για Linux</a>
 </p>
 
-<h3>Svenska: Potentiellt kritiskt säkerhetshål</h3>
+<h3 id="swedish">Svenska: Potentiellt kritiskt säkerhetshål</h3>
 <p>
 Ett potentiellt kritiskt säkerhetshål har upptäckts i Windowsversionen av Bitcoin-QT. Om du kör Bitcoin-QT i någon av versionerna 0.5 t.o.m. 0.6 för Windows så bör du stänga av programmet och uppgradera till version 0.5.3.1 eller 0.6rc4 OMGÅENDE.
 </p><p>

_alerts/2012-05-14-dos.html

@@ -4,14 +4,14 @@
 active: false
 banner: ""
 ---
-        <h2>Risks</h2>
+        <h2 id="risks">Risks</h2>
 <p>
 A denial-of-service vulnerability that affects all versions of
 bitcoind and Bitcoin-Qt has been reported and fixed. An attacker
 could isolate a victim's node and cause the creation of blockchain
 forks.
 </p>
-        <h2>Solutions</h2>
+        <h2 id="solutions">Solutions</h2>
 <p>
 Because this bug could be exploited to severely disrupt the Bitcoin
 network we consider this a critical vulnerability, and encourage
@@ -21,16 +21,16 @@ <h2>Solutions</h2>
 <a href="https://bitcointalk.org/?topic=79651">Backports for older releases (0.5.5 and 0.4.6) are also available</a> if
 you cannot upgrade to version 0.6.2.
 </p>
-        <h2>Technical Details</h2>
+        <h2 id="technical-details">Technical Details</h2>
 <p>
 Full technical details are being withheld to give people the
 opportunity to upgrade.
 </p>
 <p>
 Thanks to <a href="http://forre.st/">Forrest Voight</a> for discovering and reporting the vulnerability.
 </p>
-        <h2>Questions &amp; Answers</h2>
-<h3>
+        <h2 id="questions-and-answers">Questions &amp; Answers</h2>
+<h3 id="how-do-i-know">
 How would I know if I am the victim of this attack?
 </h3>
 <p>
@@ -47,13 +47,13 @@ <h3>
 block count, which can happen for several reasons unrelated to
 this vulnerability).
 </p>
-<h3>
+<h3 id="can-my-wallet-be-stolen">
 Could this bug be used to steal my wallet?
 </h3>
 <p>
 No.
 </p>
-<h3>
+<h3 id="can-malware-be-installed">
 Could this bug be used to install malware on my system?
 </h3>
 <p>

_alerts/2013-03-11-chain-fork.html

@@ -4,7 +4,7 @@
 active: false
 banner: ""
 ---
-        <h2>What happened</h2>
+        <h2 id="what-happened">What happened</h2>
 <p>
 A bitcoin miner running version 0.8.0 created a large block (at height 225,430) that is incompatible
 with earlier versions of Bitcoin.
@@ -14,22 +14,22 @@ <h2>What happened</h2>
 accepting, and building on, that block, and miners, merchants and users running older versions of bitcoin
 rejecting it and creating their own block chain.
 </p>
-        <h2>What is being done</h2>
+        <h2 id="what-is-being-done">What is being done</h2>
 <p>
 Large mining pools running version 0.8.0 were asked to switch back to version 0.7, to create a
 single block chain compatible with all bitcoin software.
 </p>
-        <h2>Questions &amp; Answers</h2>
-<h3>I'm not a miner or a merchant, what should I do?</h3>
+        <h2 id="questions-and-answers">Questions &amp; Answers</h2>
+<h3 id="what-should-i-do">I'm not a miner or a merchant, what should I do?</h3>
 <p>
 Nothing. Your bitcoin software will switch to the correct chain automatically, no matter
 which version you are running.
 </p>
-<h3>Are my bitcoins safe?</h3>
+<h3 id="are-my-bitcoins-safe">Are my bitcoins safe?</h3>
 <p>
 Yes.
 </p>
-        <h2>What will be done</h2>
+        <h2 id="what-will-be-done">What will be done</h2>
 <p>
 The core developers have investigated what caused the old versions to reject the new
 blocks, and have released a 0.8.1 version that avoids creating blocks that are incompatible with

_alerts/2013-03-15-upgrade-deadline.html

@@ -4,7 +4,7 @@
 active: false
 banner: ""
 ---
-        <h2>What is happening</h2>
+        <h2 id="what-is-happening">What is happening</h2>
 <p>
 If you are using an old version of Bitcoin-Qt (or bitcoind, the server bitcoin software),
 you must either upgrade to version 0.8.0 or later before May 15, 2013,
@@ -44,7 +44,7 @@ <h2 id="workaround">If you cannot upgrade to a backport</h2>
 <a href="https://en.bitcoin.it/wiki/Data_directory">Look here</a> if you need help
 finding the bitcoin data directory.
 </p>
-        <h2>Miners/mining pool operators</h2>
+        <h2 id="miners">Miners/mining pool operators</h2>
 <p>
 If you are creating new blocks (you are a solo miner or mining pool operator), then
 you should be aware that upgrading from 0.7 to 0.8 requires a lengthy
@@ -58,7 +58,7 @@ <h2>Miners/mining pool operators</h2>
 May 15th; if you increase locks before then you run the risk of creating
 or building on blocks incompatible with the rest of the network.
 </p>
-        <h2>Why this is necessary</h2>
+        <h2 id="why-necessary">Why this is necessary</h2>
 <p>
 A bug caused a <a href="/chainfork">temporary block chain fork on 11 March, 2013</a>.
 After investigating

_alerts/2013-08-11-android.html

@@ -5,11 +5,11 @@
 banner: ""
 ---
 
-<h2>What happened</h2>
+<h2 id="what-happened">What happened</h2>
 
 <p>We recently learned that a component of Android responsible for generating secure random numbers contains <a href="http://android-developers.blogspot.com.au/2013/08/some-securerandom-thoughts.html">critical weaknesses</a>, that render all Android wallets generated to date vulnerable to theft. Because the problem lies with Android itself, this problem will affect you if you have a wallet generated by any Android app. An incomplete list would be <a href="https://play.google.com/store/apps/details?id=de.schildbach.wallet">Bitcoin Wallet</a>, <a href="https://play.google.com/store/apps/details?id=piuk.blockchain.android">blockchain.info</a> wallet, <a href="https://play.google.com/store/apps/details?id=com.miracleas.bitcoin_spinner">BitcoinSpinner</a> and <a href="https://play.google.com/store/apps/details?id=com.mycelium.wallet">Mycelium Wallet</a>. Apps where you don't control the private keys at all are not affected. For example, exchange frontends like the Coinbase or Mt Gox apps are not impacted by this issue because the private keys are not generated on your Android phone.</p>
 
-<h2>What has been done</h2>
+<h2 id="what-has-been-done">What has been done</h2>
 
 <p>Updates have been prepared for the following wallet apps:</p>
 <ul>
@@ -19,7 +19,7 @@ <h2>What has been done</h2>
   <li><b><a href="https://play.google.com/store/apps/details?id=piuk.blockchain.android">blockchain.info</a></b>: Update 3.54 can be installed from <a href="https://play.google.com/store/apps/details?id=piuk.blockchain.android">Google Play</a>. Version 3.54 and above includes an automatic re-keying wizard. Simply update to the latest version and follow the onscreen instructions. Please make a fresh wallet backup after the process completes.</li>
 </ul>
 
-<h2>What you should do</h2>
+<h2 id="what-you-should-do">What you should do</h2>
 
 <p>In order to re-secure existing wallets, key rotation is necessary. This involves generating a new address with a repaired random number generator and then sending all the money in your wallet back to yourself. If you use an Android wallet then we strongly recommend you to upgrade to the latest version available in the Play Store as soon as one becomes available. Once your wallet is rotated, you will need to contact anyone who has stored addresses generated by your phone and give them a new one.</p>
 

_alerts/2014-02-11-malleability.html

@@ -4,15 +4,15 @@
 banner: ""
 ---
 
-<h2>What happened</h2>
+<h2 id="what-happened">What happened</h2>
 
 <p>Many identical transactions with different transaction IDs are being relayed on the network from an unknown source. As a result, a certain number of services like Bitcoin exchanges and wallets have been found to handle these transactions improperly and are experiencing temporary issues with their internal accounting systems. Transaction malleability is a <a href="https://en.bitcoin.it/wiki/Transaction_Malleability">known issue</a> and many services are mostly unaffected.</p>
 
-<h2>What is being done</h2>
+<h2 id="what-is-being-done">What is being done</h2>
 
 <p>Bitcoin developers are collaborating with known affected exchanges to fix their internal systems and help resuming withdrawals as soon as possible. Some pool operators have been reported to work on blocking duplicate transactions to help mitigate the problem. Emergency fixes to the Bitcoin protocol are not required and future improvements are already being discussed.</p>
 
-<h2>What you should do</h2>
+<h2 id="what-you-should-do">What you should do</h2>
 
 <p>No action is required to protect your bitcoins. Always remember to wait for one confirmation or more before spending your bitcoins. You should monitor your own exchange's website to be informed about their service status. Temporary confusion, delays and price volatility can be expected.</p>
 

_alerts/2014-04-11-heartbleed.html

@@ -5,15 +5,15 @@
 banner: ""
 ---
 
-<h2>What happened</h2>
+<h2 id="what-happened">What happened</h2>
 
 <p>The version of OpenSSL used by Bitcoin Core software version 0.9.0 and earlier
 contains a bug that can reveal memory to a remote attacker. See 
 <a href="http://heartbleed.com/">http://heartbleed.com/</a>
 for details.
 </p>
 
-<h2>What you should do</h2>
+<h2 id="what-you-should-do">What you should do</h2>
 
 <p>Immediately upgrade to <a href="/en/download">Bitcoin Core version 0.9.1</a> which is linked against
 OpenSSL version 1.0.1g. 
@@ -26,13 +26,13 @@ <h2>What you should do</h2>
 Linux users should also upgrade their system's version of OpenSSL.
 </p>
 
-<h3>Android</h3>
+<h3 id="android">Android</h3>
 
 <p>Android version 4.1.1 is vulnerable to Heartbleed. Try if you can upgrade to at
 least Android 4.1.2. If you are using Bitcoin Wallet on an Android phone, you
 should upgrade the app to at least version 3.45.</p>
 
-<h2>How serious is the risk</h2>
+<h2 id="how-serious-is-the-risk">How serious is the risk</h2>
 
 <p>If you are using the Windows version of the Bitcoin Core GUI without a wallet
 passphrase, it is possible that your wallet could be compromised by clicking

_templates/about-us.html

@@ -9,13 +9,13 @@
 <h1>{% translate pagetitle %}</h1>
 <p class="summary">{% translate pagedesc %}</p>
 
-<h2>{% translate own %}</h2>
+<h2 id="own">{% translate own %}</h2>
 <p>{% translate owntxt %}</p>
 
-<h2>{% translate control %}</h2>
+<h2 id="control">{% translate control %}</h2>
 <p>{% translate controltxt %}</p>
 
-<h2>{% translate mission %}</h2>
+<h2 id="mission">{% translate mission %}</h2>
 <ul>
   <li>{% translate missiontxt1 %}</li>
   <li>{% translate missiontxt2 %}</li>
@@ -26,25 +26,25 @@ <h2>{% translate mission %}</h2>
   <li>{% translate missiontxt7 %}</li>
 </ul>
 
-<h2>{% translate help %}</h2>
+<h2 id="help">{% translate help %}</h2>
 <p>{% translate helptxt %}</p>
 
-<h3>{% translate maintenance %}</h3>
+<h3 id="maintenance">{% translate maintenance %}</h3>
 
 <div class="credit">
   <p><a href="mailto:saivann@gmail.com">Saïvann Carignan</a><span>Website maintenance</span></p>
   <p>Garland William Binns III<span>Translation maintenance</span></p>
   <p><a href="http://dtrt.org/">David Harding</a><span>Documentation maintenance</span></p>
 </div>
 
-<h3>{% translate documentation %}</h3>
+<h3 id="documentation">{% translate documentation %}</h3>
 
 <div class="credit">
   <p><a href="http://dtrt.org/">David Harding</a><span>Coordination and writing</span></p>
   <p>Greg Sanders<span>Writing</span></p>
 </div>
 
-<h3>{% translate translation %}</h3>
+<h3 id="translation">{% translate translation %}</h3>
 
 <div class="credit">
   <p>Garland William Binns III<span>Maintenance</span></p>
@@ -59,7 +59,7 @@ <h3>{% translate translation %}</h3>
   <p>Thomas Pryds<span>Danish</span></p>
 </div>
 
-<h3>{% translate github %}</h3>
+<h3 id="github">{% translate github %}</h3>
 
 <div class="contributors">
   {% for c in site.sitecontributors %}