Implement StatusTrackingBarManager functionality

[spiralofhope]

TODO - un-check and grey-out the option

Accurate as of 8.0.1

While it's possible to manipulate StatusTrackingBarManager (the new combined status bar.. xp etc)..

• StatusTrackingBarManager is tied to MainMenuBar
• .. and MainMenuBar resets its parent, width and positioning in combat, when ActionBarPage is changed. (shift-up and shift-down for me)
• .. and manipulating MainMenuBar is impossible in combat

It appears to be impossible to implement StatusTrackingBarManager functionality.

I can hide it permanently, so maybe the solution is to hide it, get the necessary information and implement my own bar.