Updated mac project to libpng-1.6.1.
Merge branch 'master' of github.com:frogatto/frogatto
Merge branch 'master' of github.com:frogatto/frogatto
Merge branch 'master' of github.com:frogatto/frogatto
Merge branch 'master' of github.com:frogatto/frogatto
Mac project file updates.
Merge branch 'master' of github.com:frogatto/frogatto