Tickets: Time tracking

Re-written and complete Time Tracking enhancement.

This enhancement allows you to enable functions for adding just time to a ticket or enable functions to allow adding time to the thread of the ticket along with the type of time spent.

The time types are a custom list that can be modified to your business requirements giving your full billing and reporting abilities.


Pictures: -
Admin screen displaying available options
![admin-timeoptions](https://cloud.githubusercontent.com/assets/8893903/4733790/83b490bc-59cc-11e4-9108-d103b84fda12.jpg)

Ticket Header providing a time overview
![ticket-header](https://cloud.githubusercontent.com/assets/8893903/4733792/8b1905ae-59cc-11e4-842f-3fde56b86b3b.jpg)

Ticket Thread with time added
![ticket-thread](https://cloud.githubusercontent.com/assets/8893903/4733799/99ad8d24-59cc-11e4-91a8-12795b3f0006.jpg)


Post a Reply and Internal Note options when you enable thread time
![ticket-postreply](https://cloud.githubusercontent.com/assets/8893903/4733805/a64129f6-59cc-11e4-86f2-802c85e2d73d.jpg)
![ticket-internalnote](https://cloud.githubusercontent.com/assets/8893903/4733806/a9e33234-59cc-11e4-811a-1b93d6ab294f.jpg)

Time adding form when you enable Total Time adding
![ticket-time](https://cloud.githubusercontent.com/assets/8893903/4733810/b5c0af64-59cc-11e4-92a3-04dcfc516d08.jpg)