Fix styling of links (haskell-infra#271)

* Use solid underline for links instead of dotted

* Don't underline links in buttons and navbars

* Don't underline links in thumbnails

site/css/hl.css

@@ -275,7 +275,7 @@ textarea {
 
 a {
   color: #9E358F;
-  text-decoration: underline dotted; }
+  text-decoration: underline ; }
   a:hover, a:focus {
     color: #65225b;
     text-decoration: underline; }
@@ -2032,6 +2032,9 @@ select[multiple].input-lg,
     -webkit-box-shadow: none;
     box-shadow: none; }
 
+a.btn {
+  /* No text-decoration for <a> tags in buttons */
+  text-decoration: none; }
 a.btn.disabled,
 fieldset[disabled] a.btn {
   pointer-events: none; }
@@ -2762,6 +2765,7 @@ tbody.collapse.in {
     .nav > li > a {
       position: relative;
       display: block;
+      text-decoration: none; /* No text-decoration for <a> tags in navbars */
       padding: 10px 15px; }
       .nav > li > a:hover, .nav > li > a:focus {
         text-decoration: none;
@@ -3391,6 +3395,9 @@ a.badge:hover, a.badge:focus {
     word-wrap: break-word;
   }
 
+a.thumbnail {
+  /* No text-decoration for <a> tags in thumbnails */
+  text-decoration: none; }
 a.thumbnail:hover,
 a.thumbnail:focus,
 a.thumbnail.active {