Add context to ticket state name (noun) and action (verbs)

Conflicts:

	include/class.forms.php

Multilanguage Support via gettext

- added gettext encapsulations to all texts i thought necessary
- added fallback function for the case that the gettext extension isn't loaded
- added browser language detection
- added gettext to the list of optional extensions in setup
- rewritten some of the texts to use sprintf instead of appending strings
- added german translation file
- removed mark_overdue-confirm from cannedresponses.inc.php

extend multi language support and a fex fixes

- Better detection of translation files
- Added functionality to redirect language codes (see redirecting
language codes)
- Ticket Status can be translated
- The Datepicker can be translated
- Extended functionality of 'testlang.php' to show what language code is
used to translate

Forgotten to apply a patch from RC5 to RC6

- Forgotten to change $var to $vars in line 380 of class.mailfetch.php
- Removed unneeded comment

Added php_gettext as primary translation engine

- Added php_gettext support (thanks to Danilo Segan and Steven
Armstrong)
- php_gettext is now the primary translation engine
- Extended language detection functionality

Add error/misconfiguration checks and fix undefined variables

- Proofread large portion of help tips.
- Implement help tip links in YAML files.
- Fix GUI spacing of some elements.
- Add <label> tags to a few form elements.

Add client registration methods and login required checkbox

Uses a seven step procedure:
  1. (user) Fails to login twice or more
  2. Clicks the 'Forgot my password' link on the login form
  3. Submits the username or email address and triggers a password-reset
     email
  4. Clicks the link in the email and is directed back to the reset page
  5. Enters the username or email again and is logged in
  6. Password change is forced, but current password is not required
  7. Password is updated, user can continue the session without
     authenticating again

Change the config table from a column-based table to a key-value table
with namespacing. This allows several parts of osTicket to store their
respective configurations in the same table without requiring database
structure updates

'namespace' is reserved in PHP

* Collapse date settings into system settings.
* Move auto-cron setting to emails settings page.
* Move clickable urls setting to tickets settings page.

Protect againts cross-site request forgery attacks by requiring a special
form-field or header to be sent with requests that modify ticket system
data.

This meant a slight change to the AJAX ticket locking mechanism. It was
defined to lock with a GET request; however, GET requests are defined as
safe methods and should not modify backend data (such as a lock
acquisition). Therefore, the the lock acquire AJAX method was changed to
require a POST method.

Also remove old, no-longer-used staff panel include files