* Treat UAVS diffrently from manned aviation
* Added fake_traffic testing functionality,
* Added NAV_TRAFF_AVOID Hold and Landmode
* Added Behavior: HOLD Position to collision avoidance mode and implemented Landmode to collision avoidance.
Boards where no Hardware GUID is defined will send 0 as GUID.
Right now collision avoidance for more than one FMU without Hardware GUID is not possible.
We should consider adding a randomly generated HW GUID as a placeholder for legacy Boards
This is a first baseline implementation for collision avoidance with aircraft equipped with transponders. Since the drone-to-drone and drone-to-airplane system will be regulated by a standard, we do carefully avoid to do anything too fancy. This implementation allows to reduce altitude to get close to ground and land immediately or RTL. This is similar to what a human pilot would do and allows to get out of manned airspace which is at higher altitudes.
The message handling was not obeying action focused messages and high-rate messages properly before. With this change update rates track the desired rates closely. Critical high-rate messages such as ADS-B are queued additionally to guarantee that all received packets are being correctly forwarded.