Add Multi-Part and Split SMS Configs

PS 2 : Added Split SMS
PS 3 : Cleanup
PS 4 : Fixed Derp!
PS 5 : Fixed Commit msg

Change-Id: I9c9a66ea045a7fb8b20e9d378308eb7d1dc266f6

Conflicts:
	src/com/android/mms/ui/MessagingPreferenceActivity.java