osx build: remove dependency on Carbon

The only real remaining dependency I found was SetSystemUIMode() which has can be simply replaced by NSApplication:setPresentationOptions.

NB: I also tried to update scripts/osx/template/emptyExample.xcodeproj but my Xcode 5 installation seemed to re-write the entire project file (I assume it was automatically upgraded) so the diff was *way* larger than necessary. Leaving that out for now.
osx emptyProject template: remove dependency on Carbon
Merge pull request #2648 from liamstask/feature-remove-carbon-osx

[proposal] osx build: remove dependency on Carbon