pymavlink: fixed sleep time in blocking recv handling
pymavlink: fixed sequence number handling

this is what caused mavtester to lose packets
pymavlink: raise version
ardupilotmega: added MAV_CMD_DO_FENCE_ENABLE
common: added MAV_SYS_STATUS_GEOFENCE to MAV_STATUS_SENSOR field
Added MAV_CMD_DO_RALLY_LAND for rally landings