Mms: Add privacy mode notifications

This add privacy mode feature to notifications, user and message are hidden in
status bar and notifications area when privacy mode is enabled

Patch set 1-4 : Initial commits
Patch ser 5   : Slight wording change of summary string

Change-Id: I20f5fd198d51d7079345708725a58ef2c2a71b7f
Mms : Default privacy mode to off

Change-Id: I3d4037816662707c795c60e0db47f0adbb2e08ab
Merge branch 'cm-10.1' of github.com:CyanogenMod/android_packages_apps_Mms into cm-10.1