[Code Cleanup]
* [Quick Search/Performance] When using the quick search feature, text-based searches will no longer include leading and trailing wildcards by default.  This was requiring every record to be scanned in the database.  Instead, wildcards can be explicitly specified with an asterisk (e.g. *@example.com).
[Code Cleanup]
[Code Cleanup]
* [Mail/Parser] Fixed a bug in the parser where multiple 'attached_message.txt' (message/rfc822) or 'delivery_status.txt' (message/delivery-status) attachments on an incoming message were ignored and only the last one was kept.  They are now sequentially numbered like 'attached_message_001.txt'.
* [CHD-3596] [Worklists/Custom Fields] Fixed an issue where number-based custom fields didn't sort properly as worklist columns.  Rather than sorting in numerical order (e.g. 64, 256, 1024) the results were sorted lexicographically (e.g. 1024, 256, 64).  This bug was introduced by an earlier feature that separated multiple custom field values with commas, as it converted the field to text from integers.
* [CHD-3595] [Parser/HTML] Fixed an obscure issue with nonbreaking spaces in HTML-only mimeparts encoded in quoted-printable format as Unicode (=A0).  These were not being treated as whitespace, and code like hyperlink-detection was including them.
* [CHD-3590] [Worklists/Quick Search] Fixed an issue when using quick search on the ticket 'spam score' column with decimal numbers (e.g. '> 0.33').
6.5.3-dev checkpoint