Fixes #1207
tone_alarm: add EKF_WARNING tune

Conflicts:
	mavlink/include/mavlink/v1.0
Return 0 for a non-reset
Merge branch 'master' of github.com:PX4/Firmware
Do not abort on submodule init feedback
UAVCAN update for #1229
update comment about condition_global_position_valid
UAVCAN update for #1229 (windoze)
Merge pull request #1230 from PX4/posvalidcomment

update comment about condition_global_position_valid
Merge pull request #1208 from PX4/sysid_reboot

Fixes #1207
Merge pull request #1226 from PX4/filter_mode

Return 0 for a non-reset - tested 40 mins in flight.
Merge remote-tracking branch 'upstream/master' into obcfailsafe
add simplistic gps failure detection