[Code Cleanup] Updated proper capitalization style in references to WGM
* [CHD-3201] [Virtual Attendants/Mail] Virtual Attendants may now set custom mail headers when using the 'Send Email' or 'Send Email to Recipients' actions.  This is useful if you want to provide a header like 'X-Precedence: bulk' to combat auto-responder loops, or if you want to send structured information in email to an automated script.
[Code Cleanup] Replaced more instances of 'Cerberus Helpdesk' w/ 'Cerb'
* [CHD-2895] [Virtual Attendants/Mail/Recipients] Virtual Attendants may now add new recipients to conversations from ticket and message-based behaviors.
[Code Cleanup] trigger_event_history and snippet_use_history stat records are now properly cleaned up when triggers or workers are deleted.
* [CHD-2789] [Virtual Attendants/Mail/Orgs] Virtual Attendants may now set organizations as an action on ticket and message-based behaviors.  The organization may be set for the ticket or any associated addresses (e.g. sender).  For example, a VA can automatically set an organization for new senders based on their domain name.
* [Virtual Attendant/Mail/Simulator] Implemented Virtual Attendant simulator output for the 'Set owner' action on ticket and message-based behaviors.
* [CHD-3305] [Virtual Attendants/Setup] Fixed an issue with 'Setup->Virtual Attendants' where adding a new behavior on an owner tab (e.g. app, role, group, worker) didn't always refresh the affected part of the page.  This had to do with page elements not having unique IDs, and multiple owner tabs having the same event point in use.  In this case, the first tab showing the event point was improperly being reloaded, rather than the focused tab.
[Code Cleanup] Whitespace
[Code Cleanup] Pressing ENTER from the filter input box of 'add condition' or 'add action' on a VA behavior popup no longer submits the form.
* [Virtual Attendants/Usability] When adding actions to a Virtual Attendant behavior, the 'Add Action' button is now a filterable menu (like when adding outcomes) rather than dropdown.  This makes it much more efficient to filter a long list of actions because the filtering text doesn't have to match the beginning of the option, like with a dropdown.  For instance, filtering for 'Face' will quickly limit the actions to a list including 'Post to Facebook'.
[Code Cleanup] Renamed 'C4_ORMHelper' to 'Cerb_ORMHelper'
[Code Cleanup] Renamed two 'C4_*View' classes to 'View_*'
[Code Cleanup] Whitespace
[Code Cleanup] Replaced instances of 'WebGroup Media' with 'Webgroup Media'