add web platform docs notice to about dialog

src/htmlContent/about-dialog.html

@@ -9,6 +9,7 @@ <h2>{{APP_NAME_ABOUT_BOX}}</h2>
             <div class="about-info">
                 <p class="dialog-message">{{ABOUT_TEXT_LINE1}} <span id="about-build-number">{{BUILD_INFO}}</span></p>
                 <p class="dialog-message"><!-- $NON-NLS$ -->Copyright 2012 - 2013 Adobe Systems Incorporated and its licensors. All rights reserved.</p>
+                <p class="dialog-message">{{{ABOUT_TEXT_WEB_PLATFORM_DOCS}}}</p>
                 <p class="dialog-message">{{{ABOUT_TEXT_LINE3}}}</p>
                 <p class="dialog-message">{{{ABOUT_TEXT_LINE4}}}</p>
                 <p class="dialog-message">

src/nls/root/strings.js

@@ -293,6 +293,7 @@ define({
     "ABOUT_TEXT_LINE4"                     : "Documentation and source at <a class=\"clickable-link\" data-href=\"https://github.com/adobe/brackets/\">https://github.com/adobe/brackets/</a>",
     "ABOUT_TEXT_LINE5"                     : "Made with \u2764 and JavaScript by:",
     "ABOUT_TEXT_LINE6"                     : "Lots of people (but we're having trouble loading that data right now).",
+    "ABOUT_TEXT_WEB_PLATFORM_DOCS"         : "Web Platform Docs and the Web Platform graphical logo are licensed under a Creative Commons Attribution license, <a class=\"clickable-link\" data-href=\"http://creativecommons.org/licenses/by/3.0/\">CC-BY 3.0 Unported</a>.",
     "UPDATE_NOTIFICATION_TOOLTIP"          : "There's a new build of {APP_NAME} available! Click here for details.",
     "UPDATE_AVAILABLE_TITLE"               : "Update Available",
     "UPDATE_MESSAGE"                       : "Hey, there's a new build of {APP_NAME} available. Here are some of the new features:",