mixer_multirotor: topic for motor limit notification
mixer_multirotor: motor limit notification for PX4FMU
Support for termination failsafe in PWM out driver
Add command to run termination failsafe
IO firmware supports termination failsafe
support termination failsafe in IO driver
Do not enter RC override if FMU is lost and termination failsafe mode requested
Make sure we got to valid input at least once before kicking in failsafe
Introduce FMU initialised status flag, only run failsafe trap if initialized once
geofence: lat/lon is double

This is the same change as 5832948371866aec8f0c7f16b13869f270d36aad but
against the master branch.

Some time ago the type of lat and lon in the global_pos uorb topic was
changed but this use here was missed.
Merge pull request #1366 from PX4/geofencehotfix

geofence: lat/lon is double
mf checker: fix landing check, ensure feedback from all checks is sent
Merge pull request #1368 from PX4/master_mfcheck

mf checker: fix landing check, ensure feedback from all checks is sent
Merge pull request #1325 from hsteinhaus/motor_limit_fb2

Notify about multirotor motor limits
Merge pull request #1327 from PX4/termination_failsafe

Termination failsafe
Merge branch 'master' of https://github.com/PX4/Firmware
Merge branch 'master' of https://github.com/joshcurtis/Firmware