Correct pref name for retina iPad

The correct value in the prefs to start a retina iPad is "iPad Retina" (not "iPad (Retina)")
Merge pull request #75 from coronalabs/master

Correct pref name for retina iPad
Added 64-bit device definitions
added support for 64bit simulators
Merge pull request #79 from davearata/master

added support for 64bit simulators
Merge pull request #1 from phonegap/master

Pull updates from fork master