Forward port Emoji and Strip unicode support

Change-Id: I6adb081d45389adef825d8bb1e431174a4ca416f

Conflicts:
	res/layout/emoji_insert_view.xml
	res/values/strings.xml
	res/xml/preferences.xml
	src/com/android/mms/ui/ComposeMessageActivity.java
	src/com/android/mms/ui/MessagingPreferenceActivity.java