autotest: raise timeout to 7000 seconds
GCS_MAVLink: added MAV_CMD_NAV_ALTITUDE_WAIT and MAV_CMD_NAV_LOITER_ALTITUDE

this will be used for high altitude balloon launches
AP_Mission: added ALTITUDE_WAIT NAV command

used for HAB launch
Plane: implement MAV_CMD_NAV_ALTITUDE_WAIT command

this is for high altitude balloon launch
GCS_MAVLink: added LOITER_DESCEND and ALTITUDE_WAIT
AP_Mission: added LOITER_DESCEND
Plane: added support for LOITER_DESCEND
GCS_MAVLINK: work around new union with C++ issue
GCS_MAVLink: regenerate headers
Plane: split servo code out into a separate file
AP_Mission: support wiggle_time in ALTITUDE_WAIT command
GCS_MAVLink: regenerated headers
Plane: added servo wiggle in ALTITUDE_WAIT mode
Plane: added rocket parameters ACC_HOLD_THRESH and ACC_HOLD_TIME

used to hold servos still when rocket fires
Plane: added INITIAL_MODE parameter

used to start in AUTO for balloon missions
GCS_MAVLink: added MAV_CMD_DO_AUTOTUNE_ENABLE
GCS_MAVLink: regenerated headers
AP_Mission: enable DO_AUTOTUNE_ENABLE
APM_Control: allow for multiple stop calls in autotune
Plane: added support for DO_AUTOTUNE_ENABLE