Add ability to export tasks

* Preserve external storage flag on field configuration
* User gridlayout to render task's forms
* Use new roles for task's nav

Credit: Jared Hancock <jared@osticket.com>

Fixup IE and firefox rendering issues

This will allow the typeahead to wait a short amount of time before fetching
results from the backend, which will allow for request debouncing per se. In
other words, not every keystroke will signal a request to the backend to
update the results. Instead, when the user slows down typing, the request
will begin thereafter.

This begins with a layout manager for forms which will eventually be
designable via the UI for dynamic forms.

Reset permissions and change primary department and role

orm: Correctly label correlated query joins via sub-queries
orm: Fixup formatting of dates in queries
orm: Fixup mangling of parameter values with colons in sub-queries
misc: Fixup incorrect offset calculation in Misc::dbtime()
forms: search: Add ability to describe a field search
search: Fix crash searching by ticket due date
search: Fix wrong results if searching by a date field (unix epoch was not
    converted to MySQL date format)
search: Fix wrong results searching by date == or !=

Fixes #2143

This adds the concept of independent multi-thread rendering

Credit: Jared

This is required with the connection to Dept::getEmail()->send(...)

* Fix crash visiting tasks page while ticket adv search
* Fix search on custom fields
* Add search on ticket source
* Move more advanced fields to drop-down

* Log events for AJAX collaborator list edits
* Avoid extra selects for inline image handling
* Avoid using htmLawed to add target="_blank" and class="no-pjax" to links
  in the ticket thread
* Cache instances of IntlDateFormatter; seems expensive to set up
* Cache filetypes Yaml in APC if available
* Cache I18n::getDefaltLanguage() in the request
* Avoid extraneous usage of Model::_inspect and Model::$meta
* Add aggregated query support to the ORM
* Lazily compile SQL query for InstrumentedLists
* Apply `select_related` setting when setting up InstrumentedList instances
* Slight optimization in SqlCompiler::getField
* Avoid double compiling Sql annotations in the ORDER BY clause
* Cache Thread::getEntries
* Break out event types for ThreadEvent for more legible code
* Eliminate one query from Ticket::loadDynamicData
* Fix ticket number bolding if already answered
* Use dependent subqueries for ticket statistics in the queue page, which is
  significantly faster for large data sets (like hundreds of attachments or
  thread entries)
* Fixup sidebar layout on client knowledge base pages