Various additions and fixes

- Added MacDiskUtil module and classes.
- Added DebugKeys as private computed property to NativeSubclass.DictionaryCaseSensitive.
- Removed NSWindow.WorksWhenModal.Set (this is not implemented in NSWindow, only NSPanel).
- NSWindow Example: Added keystroke to turn off "Ignore Mouse Events". Otherwise, turning it on meant
  that you had to close the window or quit the app to continue.
- NSWindow Example: Locked some buttons on right instead of left to better illustrate SmoothResize.
- PopupMenuExtension.Icon: Tests for a nil value and handles it.
- NSWorkspace.RunningApplications: Checked to make sure it responds to selector, otherwise returns empty array.
- Added structure and classes to CorePrinting module.
- Added CorePrintingExample menu item and window.
- Added AuthorizationShell to Additional Modules.
- Added AuthorizationShellExample.
- Added pragmas for unused method params and variables.
- Version 168.
- Tested compilation for all platforms.