Included WebView bandwidth management. HTML refresh.

* WebView bandwidth management now part of Android L Developer Preview
* <div class="collapsible"> becomes <section>'s
* <img>s get wrapped in <figure>s
* Small text tweaks.

Included Chromium WebView user agent. HTML refresh.

Add doctype to preview template

Needed to add this because I was getting the browser user agent styles applied instead of the DCC styles. Table font-size was being set to 'medium' instead of '13px'.

StackOverflow: http://stackoverflow.com/questions/11348727/why-does-user-agent-stylesheet-override-my-styles

Updated for Android L Developer Preview.

Reworded Bandwidth text and added link to Android L Developer Preview SDK

Updated L preview link