tone_alarm: add EKF_WARNING tune

Conflicts:
	mavlink/include/mavlink/v1.0
code style only: Fix indendation in mavlink.h
Print mavlink radio module rates
Cleanup of heartbeat handling and status printing. Ready to go mainline
Add hint that heartbeats are only considered if coming from a GCS
Fix code style, no actual code edits
mavlink: TX/RX rate counters added
Pass over drivers to reduce build size
Enable UAVCAN
Update NuttX to deal with parity
Merge branch 'master' of github.com:PX4/Firmware
Do not abort on submodule init feedback