Minor changes and improvements.
I don’t trust Swift code for KVC/KVO code just yet.
Implement stub classes for all of PlayerPRO 6’s editor types.
Merge branch 'master' into Xcode6

Conflicts:
	PPMacho.xcodeproj/project.pbxproj
	PlayerPRO 6/PPDocument.h
	PlayerPRO 6/PPDocument.m
	PlayerPRO 6/Resources/Base.lproj/PPDocument.xib