LinkInterface and Vehicle uses mutexes to synchronize writing bytes to the link instead of queued signals

ArduPilot: Only force MISSION_ITEM_INT if vehicle support bit is set

Much better error reporting for Mission transfer errors

Always send MISSION_ITEM_INT to ArduPilot

Us MAV_COMP_ID_AUTOPILOT1 instead of MAV_COMP_ID_MISSIONPLANNER

Signed-off-by: Patrick José Pereira <patrickelectric@gmail.com>

Moved flight planning away from "Flight Management" to its own class. Planning does not need a connected vehicle.

When downloading mission items from the autopilot we need to retry more
agressively, so use a shorter timeout. If we don't do this, we might not
re-request a mission item in time and the autopilot has already given up
the overall mission transfer.

This fixes the case where a mission request from QGC to autopilot or a
mission item from autopilot to QGC gets lost on the link and needs to be
requested again.

By adding a member variable for the total mission item count, we can
actually correctly estimate the progress.

Break apart string of classes into their own files as all in one file became unwieldy
Expose Airspace data in a QML ready format
Split global Airspace from AirMap (Only now I figured out the reason for the pure virtual root classes)
Refactored a bunch of things to make it consistent and/or obvious

Move all airmap related stuff to its own directory

Fixed bugs the unit test found

- add multi-vehicle support: each vehicle has now a per-vehicle AirMap
  object that takes care of flight creation, traffic & telemetry
- add a base class API layer so that the interface between QGC and the
  AirMap implementation is clear, and easier to change
- removes polygon upload to vehicle (needs a better solution)

Also fixed bug with ArduPilot guided waypoint write which would trash
existing mission.

Remove/comment off debug output pollution