- sending protocol
- uorb event message & template methods for argument packing
- libevents submodule to send common events and handle json files
- cmake maintains a list of all (PX4) source files for the current build
(PX4 modules + libs), which is used to extract event metadata and
generate a json file
* commander: add check for VTOL airfame on fmu-v2
This adds a preflight check when a VTOL airframe is configured
on a fmu-v2 where VTOL is no longer included.
* commander: address code review comments