Play SOS if the SD card can't be mounted
Merge pull request #247 from julianoes/mount-notifications

Play SOS if the SD card can't be mounted
Fixed startup scripts for default platforms, needs integration with wiki to avoid similar issues
Merge branch 'master' of github.com:PX4/Firmware
Merge branch 'master' of github.com:PX4/Firmware into position_estimator_mc
Small compile warning fix for HoTT test
Merge branch 'master' of github.com:PX4/Firmware
Merge branch 'master' of github.com:PX4/Firmware into position_estimator_mc
Fixes to MAVLink HIL