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

Handle missing `intl` module
Handle crash translating the staff login banner, when the %translation table
    does not yet exist
Handle `allow_client_updates` never having been configured
Handle staff login without @lang and @extra attributes in database

Detach conversation thread from ticket to make it more generic. Any object
can now have its own thread complete with entry type and attachments.

oops: Fix crash upgrading to c7c82835

oops: Fix crash rendering ticket view

oops: Fix crash posting response to ticket

oops: Fix refresh url after ticket reply post

orm: Locate annotations after the root model's fields

orm: Add PK field check for DISTINCT aggregate expressions

When using the DISTINCT option for aggregate expressions, ensure that when a
relationship is used in the aggregate, that a single field of the remote
model's primary key is used — rather than the foreign key, since it would
never have more than one unique value.

search: Re-implement basic ticket search

oops: Couple trivial changes

oops: Fix date formatting for PDF output

oops: Fix staff profile view and update

oops: Fix canned response listing

orm: Fix crash compiling WHERE IN (nested select)

nav: Move settings/email to email/settings

i18n: Make field visibility config translatable

oops: Fix crash adding field to custom form

forms: Fix `required` flag transfer to FormField

oops: Fix bad merge on new ticket by staff

forms: Show uneditable fields on new ticket by staff

oops: Fix bad merge on client ticket view

The commit also renames some fields in department table.

Lint test rulez!

Also re-implement the "exclude answered tickets" and "exclude assigned
tickets" from open queue options.

This patch adds support for automatic date and time formatting based on a
selection of locale. The locale can default to the system or user specified
language+locale, or can be elected separately. For instance, English
speakers can pick between US, GB, and many other English speaking locales.

This also removes the need of the %timezone table and uses the timezonedb
built into PHP 5.3+. User's can now select from a much longer list of
database and no longer need to deal with the DST checkbox.

This will help if the user has "Browser Preference" selected as the
preferred language. When email correspondence needs to be sent to the user,
the browser_lang extra attribute can be used as a backup to to the user's
language preference in the event that the language preference is set to auto
(Browser Preference).

And allow for @context to add context to the bare string literal. For
instance,

    /* @trans, @context "noun" */ 'Open'

Would mark the string 'Open' translatable with context "noun".

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

Add department setting to limit ticket assignment within department to
department members only. This is necessary for departments with strict
policy on who can access tickets.

The setting doesn't limit team assignment or auto-assignment via help topics
and ticket filters.

Previously only admins and department managers could show assigned tickets
on open queue -even- when the feature is disabled globally. This pull
request extends the same previlege to all agents.

Join to staff/user tables to get current name when fetching thread entries.