* [UI/Peeks] Fixed an escaping issue in the titles of several peek popups.  Characters like apostrophes, angle brackets, and quotes were being displayed as HTML entities.  Most often this occurred on the Virtual Attendant simulator popup.
[Code Cleanup/Contexts] Marked event contexts that return 'multiple' values (e.g. watchers).  These can then be filtered out of singular target actions like 'set ticket owner'.
* [CHD-3759] [Virtual Attendants/Mail/Owner] The 'Set owner' action on Virtual Attendant ticket- and message-based behaviors can now use worker-based placeholders.  For example, if there's an 'Account manager' worker custom field on organizations, then the owner of new incoming tickets can be automatically set to to the sender's org's account manager by using placeholders.  Previously this required a rather complex Virtual Attendant behavior to accomplish the same thing.

* [Virtual Attendants/Simulator] Fixed an issue on the Virtual Attendant simulator with the 'Set owner' action of ticket- and message-based behaviors.  If a behavior variable was used to set the worker, its value wasn't being displayed.
* [Web-API/Code Cleanup] Fixed a PHP warning if an invalid 'file_id[]' parameter was given when creating a new ticket from the Web-API.
* [Web-API/Mail/Reply] Implemented a '/tickets/reply.json' request in the Web-API to simplify sending worker replies to ticket messages.  This supports all of the options on the reply form from the UI: to/cc/bcc, set custom fields, set owner, move to, set status, reopen at, etc.
6.7.4-checkpoint
Merge branch '6.7.4' into stable