Also turn on MavlinkLogTest

Instead us a Toolbox concept which hangs off of QGCApplication

- MultiVehicleManager is a Qml friendly replacement for UASManager
- Vehicle is a replacement for both UAS and AutoPilotPlugin

Allows for UI unit tests to be written:
- Ability to respond to expected message boxes
- Ability to fail test if unexpected message boxes occurs

- Also corrected system/component id usage
- Switched to new Qt5 connect api

Added:
- sequence numbers
- better filtering for image encapsulated data messages versus FTP
- directory list now contains file sizes
- open command now returns file size in data

Specifically much better testing for the handling of:
- Ack responses not being sent by server
- Getting Nak’s back from commands
- CRC failures

Also changed file validation to take into account Mock Server no longer
sending file length in first byte of file.

Also modified protocol to better support eof’s on list and read
commands.