Added NSOutlineView subclass, adjusted NSWindow and NSButtonCell subclasses to taste.

Added a (work-in-progress) outline view subclass.
Fixed checkbox behaviour in tables & outline views.
Reverted SNRHUDWindow to original, but resizable, no longer on floating
level, and without transparency.
Modified the INSTALL_PATH of the framework

Basically the same as MrAsterisco's commit, this enables use inside of
a seperate application.
Updated project settings
Fixed row drawing glitch...
Shifted stuff around, added an Inset View for display purposes.
Now with more darkness!
New, better-looking selection.
Far better-looking highlighting, but with private methods...
Fixed headers not being public, and other minor things.
Re-shifted the DEFINEs, added a PathCell class, fixed copyright notices, etc...
Fixed up copyright notices, added seperators
Scrollview draws shadow, pathcell looks better.