Add support auto email-based auto-referral. This will happen if an email is
sent to multiple departments. For example an email with TO: support &  CC:
billing will result in the ticket getting routed to "support" department and
"billing" getting a referral of the same ticket. This allows both departments
to have visibility of the ticket - which is not possible at the moment.

Move referral checking to thread class

Refer ticket to current assignee on reassignment
Refer ticket to current department on transfer

Add the initial concept of thread (tickets & tasks) referral.

* Agent & Team
Referring a ticket to an agent or team - is just like assignment without
actually assigning. If referred agent doesn't have access to the ticket's
department then they'll only have view access.

* Department
This is like assigning a ticket to the entire department. Meaning agents who
have access to the referred to department will now see the ticket - what
they can do with the ticket will depend on the assigned role in that
particular department.

It's important to note the ticket will technically be still the
responsibility of the primary department. Transferring the ticket is the
sure way to relinquishing the responsibility.

* Auto Department Referral via email
This will happen if an email is sent to multiple departments. For example an
email with TO: support &  CC: billing will result in the ticket getting
routed to "support" department and "billing" getting a referral of the same
ticket. This allows both departments to have visibility of the ticket -
which is not possible at the moment.

This addresses issue 3815 where searching by User's phone number doesn't
work in v1.10. This adds phone number search capabilities for the User
Directory and User Search popup in v1.10.

Limit the departments based on Agent's access

Currently only windows of a specific number of days is supported. Things
like `last month` are much more complex.

The ticket status search field was supposed to mimic a text field rather
than a drop-down field like the status selection.

Also, since select "TicketStatus / State" from the drop-down list doesn't
work, remove items from the drop-down in the advanced search dialog and
queue management page which would duplicate fields already available or
selected in the list of fields already displayed.

Fixes the SQL generated for scans by staff_id and team_id on the ticket
table. The fields are not nullable. Instead, the value `0` represents not
having a value.

This allows a queue to define conditions which apply to the entire row, so
that all the columns in a row can react to a particular condition. For
instance, rows in the ticket queue for tickets due in the near future or
assigned to a particular team could be formatted a certain way.

'twas a copy+paste hazard from when it was created.

Adds the ability to "Clone" a queue, which would be nice to create a queue
similar to the current one with a couple distinct settings, but also not a
child of the queue. Also adds the ability to add a "Sub Queue" to the current
queue, which will allow easy creation of queues which are pre-configured for
inheritance.

This fixes an issue where spacing is reserved on the navigation bar on the
right side for an overflow menu, even if the overflow menu is not visible (not
necessary).

If an advanced search was committed with a validation error, the returned form
would shake and reveal the validation error; however, it would also include the
ajax redirect information next to the buttons at the bottom.

This adds the ability to add a list of avatars to a column in a ticket
queue.

Also, fix queue paths created at installation time.

Add support for different intervals for 'n [days] ago', where days can be
changed from minutes to months. Also, add support for 'more than n days from
now' and 'more than n days ago'. Useful for finding stale items.

Also, fix the display of the 'n days ago' when describing the criteria.

Turns out the pagination system is somewhat chicken and egg with respect to
determining the number of pages. The query needs to be sent to the database
to fetch the page content so that the database can also count the total
number of records available.

- %queue_sorts needs to exist before queues are inserted
- old queue id numbers need to be moved up to make room for initial queues

- Fix crash on new ticket
- Fix crash on user and org dialog popup from ticket
- Fix missing queue mass-action buttons

This originates from an ORM issue, where the select_related in a queryset
was not honored by the compiler. Therefore, the query would not include all
the fields requested and would require extra trips to the database for some
queries.

This is especially important for unbuffered queries, such as those used in
the export process, which be fetched in parallel with other queries.

Also fix SQL issue with the tables installed in the install script

This patch implements Nathan's mockups for adding sorting options to the
custom queues. The sort drop-down feature was added for v1.10. This patch
adds the complex sort dropdown back into the custom queue feature, but also
makes the sorting options customizable.