commander: Formatting and logic flow cleanup, no functional change
commander: Default all leds to off
Merge branch 'master' of github.com:PX4/Firmware into prearm_checks
Add mavlink_fd to all commander arm transitions to provide user feedback why the arming command failed
commander: Make mavlink_fd in arming command non-optional
Merge branch 'arming_feedback_fix' into prearm_checks
commander: Add pre-arm check for main sensors.
Remove duplicate code in the arming check
commander: Remove prearm test print statements
Merged master into prearm_checks
Merge branch 'warning_fixes_v3' into prearm_checks
Merge branch 'master' of github.com:PX4/Firmware into prearm_checks
commander: Notify negative on manual arming fails
Merge branch 'master' of github.com:PX4/Firmware into prearm_checks
Merge pull request #1078 from PX4/prearm_checks

Prearm checks