Joomla 3.x Support

- Joomla 3.x Support
- Support for responsive designs (i.e no pop up for reply, removed some
tables, css added)
- better Form validations
- Icons for Ticket state in Tickets view
- Bugfix: Ticket creation time
- Sort tickets in tickets view with last changed
- Update language files
- loading image on reply
- removed overriding error message from plugin authentication if not
logged in joomla