Move collaboration implementation to thread level

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

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 reworks the tabs CSS and javascript coding to be more flexible and to
support vertical tabs. (Bootstrap calls this stacked.) The javascript also
allows the URL to include the hash-tag of the last-clicked tab so that the
tab can be automatically shown when the page is reloaded.

After testing 1.9.4 I noticed that these strings are not yet included in the translation. So this is the (hopefully correct) pull request to add them ;)

Link to org & user landing pages & kill pjax on internal pages

Change z-index to overlay popup windows correctly

Show ticket prview when a ticket number is clicked as opposed to ticket
view.
Add collaborator preview tab on ticket preview tool tip.