Shefki:
	- Allow for fader modules to have priorities less than the default.
	- Ticket #719: Add a priority system to the fader module system.
	Fader modules can now return an optional priority parameter as the 2nd
	return from their GetOpacity function.  If no priority is returned then
	it will be treated as priority 0.  The lowest opacity of the highest
	priority module will be used.  This allows modules to be written to
	force the opacity to be higher instead of simply lower.
	- Just call the Focus frame Focus in LuaTexts like the rest of PB4.
	We were using Focus-target as DogTags was using.  But this is terribly
	confusing when there is a Focus' target frame.
	- Convert the mouseover handling for LuaTexts to events.
	This is far more efficient since it's not updating on a polling basis.
	- Fix the show overheal option for the VisualHeal module.  It was always
	using the setting for the currently selected layout in the config section
	regardless of the layout for the frame.
	- Avoid an error in showing the FocusFrame since blizzard removed
	FocusFrame_Update()
