[Code Cleanup] Fixed an issue where CSS Styles-to-Inline was corrupting multibyte strings due to the use of DOMDocument::loadHTML() when a meta-header for Content-Type wasn't provided.
[Mail/Drafts/HTML] Resumed drafts will now switch to HTML mode if that's how they were saved.
[Code Cleanup/HTML] The original_message.html attachments and Markdown preview code now provide explicit Content-Type and charset HTTP headers.  The Markdown preview wraps the generated HTML fragment in html/head/body.
[Mail/Queue/HTML] Implemented HTML compose and reply support in the mail queue.
[Code Cleanup] Fixed a Javascript error when the file chooser popup closes that was due to the iframe.load event firing more than once.
* [Mail/HTML/Broadcast] Implemented HTML message support in ticket worklist broadcasts from bulk update.
6.6-dev checkpoint