* [Mail/Parser/Performance] The 'original_message.html' attachment is now created more efficiently for new incoming messages.  Previously its contents were written to a temporary file that was then read into long-term storage.  Now it is saved directly from memory into storage.  This improvement also made it easier to modify the contents of the HTML message to improve usability (e.g. rewriting links for inline attachments to Cerb URLs).
* [Mail/Parser/Usability] When viewing an original_message.html attachment in the browser, inline images will now be properly displayed in the content.  For instance, this is useful when customers send screenshots by embedding them in the middle of their reply.  Previously, such images were included as attachments on the ticket but they weren't displayed in the HTML contents (technical note: The IMG tags still referenced the MIME content-id header).  These IMG links are now rewritten to use Cerb file paths.  This process works for all new messages that are received in version 6.6 or later, but it will not fix existing original_message.html attachments.
* [Devblocks/Platform/Markdown] Added the Parsedown library <http://parsedown.org/> to Devblocks.  This is a faster, leaner, and more modern replacement for the existing PHP Markdown Extra library we've been using up to this point.
[Storage/Code Cleanup] Improved the style of the Setup->Storage->Profile page.
* [Setup/Storage/S3/Usability] When testing a new S3 storage engine profile, a temporary object will be saved, read, and deleted to verify that the credentials work for all actions.  Previously the contents of the bucket were listed, but this didn't verify that content could actually be stored and retrieved.

* [Setup/Storage/S3/Usability] The S3 storage engine now supports a 'Path prefix' configuration option.  Previously all content was saved starting at the top-level of a bucket.  Now a single bucket can be shared between multiple instances of Cerb.

* [Setup/Storage/S3/Security] When configuring the S3 storage engine, the secret key parameter is no longer displayed in the profile popup form.  If left blank it will remain unchanged.  This is far more secure than transmitting it.
[Devblocks/Platform/S3] Updated amazon-s3-php-class from 0.4.0 to 0.5.1-dev
* [Storage/Performance] The storage service now has the ability to queue multiple delete operations to perform them in a single transaction.  This is useful for storage engines where incremental deletes would be very expensive.  For instance, S3 would generate an HTTP request per file being deleted, which could potentially be hundreds or thousands.  Waiting for that many HTTP requests during cron.maint is undesirable.  It is now possible for hundreds of objects to be deleted in a single request.

* [Setup/Storage/S3/Usability] Implemented batch delete functionality in the S3 storage engine.  Up to 500 objects can be deleted from S3 in a single HTTP request.
[Code Cleanup] Increased the form field input lengths for the disk and database storage profile config popups.
6.6-dev checkpoint