Add ability to disable use of authentication tokens on ticket links

Add a checkbox option within the department setting to disable the "Claim on
Response"

Feature must be enabled globally in order to be disabled locally (duh!)

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

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

Add ability to export tasks

Reset permissions and change primary department and role

Also make forms deleteble by marking them as deleted and hiding them from
the form listing. This ensures that custom data always has a link back to
the form.

Add Agents and Users setting pages
Move global settings to System settings

The setting is no longer ticket thread specific. Disabling html is now
system wide setting for disable-able textarea widgets as well as email
correspondence.

Settings for storage backend and general max size setting for agents

Fixes #1809

Refactor filter.yaml and related code base
Move isBanned routine to banlist class and make it banlist specific
Refactor how canned responses get list of filters

Fixes https://github.com/osTicket/osTicket-1.8/issues/1673

Add ability to add tasks to tickets.