[TestFlight] => Use native constants for Options

I mapped the native NSString constants from the library, to use them
with the Set… methodes. Some of the old settings didn't work. So they
were not even used.
[TestFlight] => Renamed the options
[TestFlight] => Update sample app

The sample app has been updated to the latest bindings. With the use
off all the possible settings for TestFlight
Merge branch 'master' of github.com:svrooij/monotouch-bindings into svrooij-master

Conflicts:
	TestFlight/binding/testflight-threadsafe.cs