Copter: bugfix to condition-yaw for relative angles

Thanks to roque-canales for raising the issue and paradisephil for finding
the specific piece of code that went wrong and suggesting the fix.
VRBRAIN: modified target clean
DataFlash: Added four more channels for logging
AP_Compass: VRBRAIN. Deal with external mag connected on internal I2C on VRBRAIN 4.5
This enables user to set the external parameter to true even if only one compass is connected
VRBRAIN: defined AirSpeed inputs for ArduPlane on VR Micro Brain 5
VRBRAIN: added flag for to build versions with different kind of RC Inputs
VRBRAIN: added new board VR Brain 5 PRO
VRBRAIN: added script for build all VirtualRobotix binaries
Copter: enable mount control with channels > 8 for radios with SBUS.
VRBRAIN: Added tone_alarm for VR Brain 5 and VR Micro Brain 5
VRBRAIN: disabled buzzer for VR Brain 5 PRO