* [Platform/Plugins/Popups] Plugins that use genericAjaxPopup() can now specify the 'target' option using a jQuery Position object; e.g. { my: 'top left', at: 'bottom right', of: 'selector' }.
* [CHD-3622] [Explore/Usability] Improved the way the last accessed time is recorded for explorer sets.  Previously the access timestamp only updated 20% of the time in order to reduce extraneous UPDATE database queries when someone quickly paged through the list.  Now, instead, the access time is updated any time at least 30 seconds has elapsed since the last recorded access time.  Additionally, the access time is now always recorded when the set is created.  The prior inefficiency rarely caused problems, but it would manifest if an explorer set was created shortly before the maintenance scheduled job ran, or if the maintenance job was set to run very often instead of nightly.  This could result in explorer sets being purged while they were still in use.
[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
* [Mail/HTML/Broadcast] Implemented HTML message support in address worklist broadcasts from bulk update.
* [Mail/HTML/Broadcast] Implemented HTML message support in opportunity worklist broadcasts from bulk update.
[Code Cleanup] Escaped HTML in ticket worklist broadcast previews.
* [Mail/Usability/HTML] When generating a plaintext part from an HTML-only message, Cerb will now attempt to preserve whitespace in pre-formatted (PRE) and CODE blocks.
[Code Cleanup] DevblocksPlatform::stripHTML() now provides a $strip_whitespace argument.  This allows the function to also be used when generating HTML->Text mime parts.
[Code Cleanup] DevblocksPlatform::stripHTML() now condenses multiple linefeeds more efficiently.
* [Mail/Usability/HTML] When generating a plaintext part from an HTML-only message, Cerb will now attempts to prefix nested BLOCKQUOTE content with '>'.
* [Mail/HTML/Usability When sending HTML mail, Cerb will generate a new plaintext part that cleans up Markdown formatting.  This plaintext part is sent along with the HTML message (e.g. for mobile and automated mail readers), and it's also what's stored in the conversation history.
* [REVERT] [Platform/Popups/Usability] Popups no longer open up in the center of the browser window by default.  This was causing problems on popups that grow, since they could expand beyond the bottom of the window and constantly require being dragged into place.  Popups now display at the top so they have the full browser height to grow before they show a scrollbar.  When a popup is opened a position can be defined now, so popups that don't grow (like the file chooser) may still elect to show up in the center of the page.
6.6-dev checkpoint
* [Setup/Mail/Reply-To/HTML] Reply-to addresses can now specify a default HTML template for outgoing mail. The template set on the default reply-to address is the global default.  When a group doesn't have its own HTML template it will default to the one on its reply-to address.