Also:
- Remove unused code

This was done to support both PX4 and APM flight stack with same code

- Also added new adjustMavlinkMessage support

- New MissionManager
- Plumb MissionManager through MissionEditor
- Mission Editor supports get/set

- Restructured a number of MissionItem properties as well

Plus lots of other cleanup

- Moved all MavManager functionality to Vehicle
- Updated all code to use Vehicle instead of MavManager
- Removed MavManager

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

This can only come from the heartbeat

- FirmwarePlugin is the new place for code which is specific to
firmware flight stack
- FirmwarePlugin currently supports flight mode apis
- Modify code to use new FirmwarePlugin support

Added gaussian noise function.  Currently noise will not be added to measurements unless a user changes the initialization value and builds from source.

Added setter functions for HIL noise variances.  Researching methods to add zero mean gaussian random number before implementation