Instead us a Toolbox concept which hangs off of QGCApplication

Also merged MissionController and MissionEditorController into single
MissionController implementation

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

Also many LinkManager API changes to further isolate all link
management inside LinkManager.

Also turn them back on

- Updated MainWindowTest to catch this problem
- Also implemented initial pass at SetupView unit test

- Updated MainWindowTest to catch this problem
- Also implemented initial pass at SetupView unit test

Now works for more than Serial links

Simple starting point to view testing

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

Used for unit testing