Plane: improve LOG_BITMASK docs
AP_Math: added equality operator for VectorN
AP_Notify: reduce the latency in the main task of LED updates

the ioctl now gets called in a IO timer callback
Plane: update docs for RSSI_PIN for pixhawk
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