Plane: tweak autotest gains for plane
GCS_MAVLink: added new COMPASSMOT_STATUS message
Copter: added compassmot over MAVLink

use the MAVLink interact code to allow for compassmot over MAVLink

Pair-Programmed-With: Randy Mackay <rmackay9@yahoo.com>
Copter: more checks before starting compassmot

additional checks that copter is landed and that compassmot calibration
isn't already being performed.
Returns ACK to ground station as process begins
GCS_MALink: improved generate.sh failure msg
GCS_MAVLink: regenerate for COMPASSMOT_STATUS msg
Copter: remove remnant of cli compassmot