Objj2 compiler fixes

Compiled all files individually:

- Added missing imports.
- Added @class/@global declarations to break circular dependencies.
- Fixed broken code in CPCharacterSet -hasMemberInPlane:
- Misc. code cleanup.
Objj2 compiler fixes

Compiled all files individually:

- Added missing imports.
- Added @class/@global declarations to break circular dependencies.
- Misc. code cleanup.

Conflicts:
	AppKit/CPWindow/_CPWindow.j
	AppKit/Platform/DOM/CPPlatformWindow+DOM.j
Objj2 compiler fixes

- Each file compiles individually with no errors or warnings.
- Added missing imports.
- Fixed imports to remove circularity.
- Removed unnecessary imports.
- Added missing headers.
- Added missing action_button.png.
- Replace CPMakeRect with CGRectMake.