Joystick: Added new library for lower-latency joystick.
Plane: Add new Joystick library reference.
Merge remote-tracking branch 'mike_origin/js_lib' into matt_dev3
Plane: squash me
Merge remote-tracking branch 'mike_origin/js_lib' into matt_dev3
Attitude: Added failsafe handling for joystick
GCS_Mavlink: Changed to use joystick parameters
GCS_MAVLink: added generated messages
AP_Joystick: Added definition for enabling parameter