Make the new ticket form more intuitive (move things around)

Make sure SLA plan is 'active' when marking tickets overdue.

Self merging.

Use the actual error message set in Staff::login instead of boring "Authentication Required";

Use the improved login function
Redirect to ticket view on successfull login.

* No longer redirects - simply returns usersession obj.
* support error setting - shown on login page in place of "Authentication Required";

change tryLogin to simply login

Imrove internal notes posting
Improve ticket assignment & alerts

 e.g %{staff.*} can be overwritten by a string (placeholder) as assign('staff', 'SYSTEM').

Improve variable's preg_match_all (Thanks to Jared)

Reviewed-By: Peter Rotich <peter@osticket.com>

Reviewed-By: Peter Rotich <peter@osticket.com>

Self merging.