AP_NavEKF : modifed Zaccel bias noise parameter to prevent unstable bias estimate
Copter: removed check on target component in arm

Thanks to DonLakeFlyer for finding this, see
https://github.com/diydrones/ardupilot/pull/909
Plane: removed check on target_component in ARM/DISARM

Thanks to DonLakeFlyer for finding this, see
https://github.com/diydrones/ardupilot/pull/909
AP_Relay: fixed Pixhawk relay pin numbers

thanks to Craig for spotting this!