KPN's first commit for safety check
Got it to build
Safety check works
Comments etc
finally fixed submodules?
Merge branch 'submodule_fix_2'
Merge remote-tracking branch 'origin/odroid_safety_check_fix'

Conflicts:
	mavlink/include/mavlink/v1.0
finally fixed submodules!
updated mavlink lib
update mavlink
update mavlink
added mavlink receive for odroid command
Changes for new MAV msg - doesn't work yet
Merge branch 'mav_add_safety_switch' of https://bitbucket.org/idtech/px4_firmware into mav_add_safety_switch
Var names changed
Added new message - needs to be tested
added play tune command and custom tune for warning sound
Safety-switch check works
updated mavlink, added tone
Merge branch 'mav_add_safety_switch' of bitbucket.org:idtech/px4_firmware into mav_add_safety_switch