Use older PreferenceActivity.

Builds with SDK version 9 (2.3).
Add PopupMenu replacement for 2.3
(Android) abstract PopupMenu to make Dalvik happy on 2.3
(Android) move @TargetApi to correct location
Merge branch 'android-2.3'

Conflicts:
	android/phoenix/src/org/retroarch/browser/RetroArch.java
	android/phoenix/src/org/retroarch/browser/SettingsActivity.java