[Code Cleanup]
* [Search/Usability] Fixed a PHP notice when performing a full-text search without a default 'max results' value.
* [CHD-3927] [Worklists/Custom Fields] Fixed an issue when filtering a worklist by a multi-value custom field where the 'not in' operators didn't work properly.
* [CHD-3917] [Virtual Attendants/Mail] Fixed an issue with 'Before sending worker message' behaviors where custom mail headers weren't being set when composing new messages.
* [CHD-3811] [Mail/Snippets/Keyboard] Fixed an issue with the Ctrl+Shift+I shortcut on mail compose/reply where it formatted with italics rather than focusing the snippets quick search.
* [CHD-1802] [Records/Custom Fields] Fixed an issue where custom fields could be set on record #0 if a record failed to be created (e.g. an invalid email address).
* [Mail/Parser] When converting HTML to plaintext, the email parser now provides special handling of Microsoft Word-formatted quotes, apostrophes, and ellipses.
* [CHD-3953] [Snippets/Windows] Fixed an issue with snippets that contain CRLF (carriage return + line feed) endings.  When these were inserted into a reply, the cursor would advance an extra character beyond the inserted content for each invisible CR.
* [CHD-1967] [Setup/Workers] The worker edit popup now enforces valid email addresses in the UI.
* [CHD-3114] [Mail/Drafts/Links] When composing a message from 'Create + Link' on the Links tab, the resulting draft will now currently remember the link to the current record.
* [Profiles/Usability] On the Links tab on profiles, the 'Create + Link' popups now open at 750px default width, like 'Find + Link' already did.  Previously the create popups opened at 500px width, which is pretty small on modern displays.
* [CHD-3823] [Scheduler/Import] When importing worker records from XML files, existing MD5 hashes will be converted to Cerb's salted SHA1 password format.
6.8.4 checkpoint
Merge branch '6.8.4' into stable