Add Deskbar clock settings to Time Preferences

* Added a new Clock tab to the Time preflet. Added Clock related
controls there. They all function by communicating with Deskbar.
* Put controls in a BBox controlled by the Show clock checkbox.
This more clearly shows that all the clock settings are dependent
on the show clock setting since it doesn't matter what your clock
settings are if you don't show the clock.
* Make revert work.
* Split clock settings into it's own file and struct.
* Re-add the time zone setting.
* Remove the clock settings from the Deskbar preference window, they
are in Time now.
* Make Locale preferences accepts B_LOCALE_CHANGED message, although
not used.

Add Deskbar clock settings to Time Preferences

* Added a new Clock tab to the Time preflet. Added Clock related
controls there. They all function by communicating with Deskbar.
* Put controls in a BBox controlled by the Show clock checkbox.
This more clearly shows that all the clock settings are dependent
on the show clock setting since it doesn't matter what your clock
settings are if you don't show the clock.
* Make revert work.
* Split clock settings into it's own file and struct.
* Re-add the time zone setting.
* Remove the clock settings from the Deskbar preference window, they
are in Time now.
* Make Locale preferences accepts B_LOCALE_CHANGED message, although
not used.