Added INWindowButton to allow customization of the window titlebar buttons.
Updated property names, handling window becoming is resigning key, handling disabled button state.
Fixed flickering when pointer between buttons, correctly reseting rollover state when window resizes, refactored code a little.
Removed unneeded graphics
Added INAppStoreWindow.fullScreenButton property, hiding INWindowButton when window goes fullscreen.
Updated source file leader comments.
Releasing ivars in non-ARC environment.
Updated header documentation
Moved public setters from Private section to Accessors
Drawing window's title.
Fixed header doc.
Added title text styling properties.
Setting button's target and action in the setters. Updated readme.
Merge pull request #90 from beefon/master

Traffic light buttons customization, title drawing