Fix wrong API level check using save method

Change from Android Gingerbread (API 9) to Android Honeycomb (API 11)
Fix wrong API levels in project files.

Fix Android sample app and instrumentation test project project
targetSdkVersion (to 11).
Migration feature

Add migration feature as a factory class called SecureFactory,.
Use it to create a SecureSharedPreferences from an existing
SharedPreferences instance (or load one from disk).