Frameworks: Port hardware key rebinding
squahsed commit 0f cherry picks from
Cyanogenmod:
   Framework: Forward port Long press back to kill app db3817d
   Hardware key custom rebinding (1/2) b055725
   Framework: Bring Long press back kill app toast back 08641ec
SlimRoms:
   More options added to hardware key rebinding (1/2) 22bd763
   Fix issue with hardware keys KEY ACTION comparisons. 4812ee5
   Framework: Add Home/Back buttons available for rebinding (1/2) 5f20d08

removed code for hardware key expanded desktop actions
removed code for hardware key notification shade toggle