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

* Fix crash saving a page (regression)
* Fix red banner deleting a department
* Fix crash deleting a knowledgebase article

Also fix crash rendering db timezone on PHP 5.3

* Fix attachments not sticking on new dynamic form entry
* Fix attachments not sticking on thread post validation error
* Fix missing inline images in FAQ article viewing
* Fix missing inline images in FAQ article printing
* Fix crash rendering sidebar in staff faq view with attachments
* Rewrite GenericAttachments to be an ORM object
* Port CannedResponse to ORM
* Fix attachments not being displayed when editing a FAQ article
* Fix squirly empty blue box on faq articles with no attachments

Also, fix clearing users in an organization when removing the organization.

This patch attempts to query or detect the Olson style timezone
(e.g. America/Chicago) from the database. This is preferred over the
previous code as the previous code would always consider the current
database GMT offset rather than the GMT offset of the date being converted
(which might be on the other side of a DST transition).

This fixes a bug where the search queue would be empty when accessing it via
the navigation link

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

* FAQ Articles
* FAQ Categories
* Access templates

Also, add mass delete user with tickets