AP_Arming: more detail in ARMING_CHECK docs
Copter: remove unused RELAY_TOGGLE definition
Copter: fix compiler warning from motorsync test
Copter: remove unused RADX100 definition

The real purpose of this small change is to kick off the autobuilder for
the AC3.1.1 release.
Plane: consider GPS unhealthy if it doesn't have 3D lock
Rover: consider GPS unhealthy if it doesn't have GPS lock
Rover: update to 2.45
Plane: prepare 2.78beta1
DataFlash: added baro dataflash logging
AP_Airspeed: expose get_temperature()
Plane: added baro and airspeed logging

including raw temperature and pressure values
Plane: prepare 2.78beta2
Plane: added RSSI_RANGE parameter
AP_Airspeed: fixed example build
AP_InertialSensor: fixed example builds
AP_Math: fixed example build
AP_Notify: fixed example build
Plane: prepare for 2.78 release
Copter: firmware to AC3.1.2-rc1
Copter: remove unused compat.pde entries