Don't display the Close Task option if the current user can't close it...

This addresses issue 3782 where clicking Print on a Task gives you a blank
popup that hangs. This is because the Print button was being treated as a
Task action when it is actually not one. This adds a ternary operator to
give the proper Task Actions the `task-action` class and gives the Print
button no class.

Use class instead of id on form element that triggers overlay on submit.

This is my attempt at removing similar texts from the translator work load.
It also makes an attempt at dropping some misspelled words and works toward
standardizing some phrases.

Make tasks actions icon based buttons
Fix task assignment issue

Add a preference option to set the sort order of the thread entries in DESC or
ASC order.

 * System Default order is ASC
 * Auto-scroll is disabled when sort order is set to DESC.

Redirect to recent queue / listing on transfer or assign

Disable pjax on task print

- Tickets cannot be closed when an open ticket exists
- Tickets/Tasks cannot be closed when required for close fields are missing
data
- Add isCloseable routine to ticket/task classes

Add danger to delete actions.

Revert this commit once fixed.

* 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>

Add multiple sticky bars support
Make scroll-up automated and independent

Move collaboration implementation to thread level

Add a tab for tasks
Add mass action for tasks

This patch converts the central file and threading classes over to use the
ORM.

Allow for permissions to be registered dynamically. This will
allow for the ability for models and plugins to register permissions.

Add ability to add tasks to tickets.

Introduce the initial concept of adding tasks to a ticket.