So, fields with only the 'required' flag set for users are shown for the
registration page.

This greatly improves the performance collecting user and organization
ticket statistics.

The previous code would erroneously include ticket counts from the user's
organization even if the user did not have access to them.

Use `if not exists` in the create statement for the %cdata table so that, in
some race conditions, a MySQL slave would not be crashed because of an
already-existing table.

The previous code resulted in rebuilding the %thread_entry table several
times during the upgrade process. For systems will several hundred or
thousand megabytes of content in their system, this could result in a very
slow or crashed system.

This patch avoids multiple rebuilds of the table by simply creating a new
one and copying the correct values into the new table. It also avoids
possible duplicates when changing collaborators to the new thread system
considering that collaborators were not properly removed with tickets in
previous versions.

The previous logic required the Ticket::PERM_ASSIGN permission in order to
open a ticket. This logic requires that perm only if attempting to assign
the ticket on open.

Redirect to recent queue / listing on transfer or assign

Department/Topic create now considers the possibility of preset id (primary key)
Default help topic routing to floating system's default department

SendAlert expects an array as options param.

Utilize the same template for tickets and tasks queues

If enabled globally. Also, keep the columns consistent on search results.
Lastly, actually show _only_ unassigned tickets (not either unassiged to
staff or team)