Update to UE4.6 & Myo Beta 7

-Contains compile fixes to sync code base to UE4.6. Note that warning
C4273 is suppressed due to 4.6 changes to Input Mapping.
-Syncs Myo SDK to Beta 7 (0.7)
-As per 0.7 Thumb to Pinky is now DoubleTap
-Added locking mechanism, this plugin defaults to none, but you can call
SetLockingPolicy on your MyoComponent to change this on say BeginPlay.
-As per 0.7 Added Lock/Unlock functions on MyoController class
-Arm Orientation space now persists throughout PIE sessions, will only
get lost when quitting app.