Preferences window added to app.
PreferenceViewController used as a host for concrete preference windows.
Wrong use of extern in .m file.
Merge branch 'develop' into feature/#65_add_support_for_optipng

Conflicts:
	SpriteBuilder/SpriteBuilder.xcodeproj/project.pbxproj
OptiPNG settings added to project settings.
Extracted a few methods: reuse and readability. Added some commented out NSLogs for debugging purposes.
Extract methods for -publishDirectory to create file list. Renamed param. Removed local app delegate var, only used once.
Cut -publishDirectory down to a small method, layering the different process in more abstraction levels. Moved original local vars down to the different extracted methods where they are actually needed.
Formatting of code: indentation.
SpriteSheetPacker Tupac returns now a list of files created.
Published png files stored in set. Removed some debug NSLogs. Renamed some local var to be more self-explanatory.
Renamed project settings property, it didn't make sense.
OptiPNG run as last step in publishing process.
Still some tweaks needed: Skip if file is up to date, update progress window, add warnings.
Removed Preferences window, not needed at the moment. OptiPNG will be bundled with the app.
Usage info added to preferences controller.
Preferences controller removed.
OptiPNG added as binary to bundle.
PopUpButton for publish environment added to main toolbar. Removed checkbox in project settings.
Publish environment saved in project settings.
Bitmap fonts optimized as well. Logic for cleaning up moved completely to CCBPublisher.
OptiPNG stderr output added as warnings.
File view background color is light grey again.