* Fix warning for negative unix timestamps in Misc::db2gmtime
* Fix crash because of parser context passed to getXxx functions
* Fix inability to update email address

This patch attempts to query or detect the Olson style timezone
(e.g. America/Chicago) from the database. This is preferred over the
previous code as the previous code would always consider the current
database GMT offset rather than the GMT offset of the date being converted
(which might be on the other side of a DST transition).

This patch includes a slight database migration, and adjusts the
functionality of a few core components.

  * Move collaborators from the ticket to the thread.
    This concept allows collaborators on any object which has a thread,
    including tasks.

  * Add flags to the thread entry
    This will allow flagging thread entries for different purposes.
    Initially this can be used to flag the original message of a thread in
    case a ticket / thread is created without an initial message.

  * Lock becomes more of a utility
    The lock is now disconnected from the ticket and is a separate utility.
    Separately, the ticket and task objects can have a reference to a lock
    object. Furthermore, when submitting some activities to tickets, the
    lock is verified to be owned by the respective agent, and the lock code
    must match a current lock code. The code is rotated on each acquire()
    call to guard against double submissions.

  * Collaborator is an ORM model
    The TicketUser class is broken up now so that the collaborator instance
    can exist apart from a ticket. Email message ids are now generated for
    collaborators without respect for a ticket so that collaborators can be
    properly supported on any thread.

Misc::randCode does not generate significantly random data for Windows
platforms with a local database. This stems from the random seed using the
milliseconds from the current time of day and the database connection time,
in microseconds. Because Windows has especially poor sub-second time
resolution via the microtime() function, the seed does not have many
variations.

This patch addresses the issue by using the included Crypto::random()
function as a source of random data rather than the mt_rand() function, as
it uses native cryptographic random data generators if possible to generate
the data, and uses microtime() as a fallback if no other source of random
data is available on the platform.

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.

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

Use the admin-configured time format for formatting the values in the time
dropdown as opposed to always using 24-hour time.

Process inline attachments in thread entry and support inline images in
piped emails

Support inline images across the system, with draft support

Migrate to a single attachment table
    That way we don't need a new table for everything we need to attach an
    inline image to (like a signature, for instance)

Add richtext support for internal notes

Implement images on site pages

* Image paste in Redactor
* Make non-local images optional
* Placeholder for non-local images
* Fix local image download hover
* Don't re-attach inline images

Also, allow for the administrator to manually define the ROOT_PATH in the
config file (the very last mile).

If unable to detect the root path, provide a fallback ROOT_PATH setting to
'./'. This is likely to happen if run from the commandline (like for crons)
or if DOCUMENT_ROOT and the folder of main.inc.php seem to have nothing in
common

Fixes #704

Use mysql connection timing as the random seed, along with the microseconds
of the current time.

Change href definitions for embedded links in the ticket thread so that the
click will be bounced through a script. This will hide the original referrer
URL where the link originated.