Plus lots of other cleanup

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

Moving methods from MainWindow to QGCApplication so that more things
can run without a window. Helpful for testing.

Also fixed typo in offline waypoint editing message.

also adds AMSL output in ft

Also added translation calls for some UI messages.

Fix for static const float cannot be initialized within a class definition, and other windows compile errors.

The right click menu will only show up when connected to an APM autopilot,
since this feature is APM only.

view only" functions and renamed some of the old functions. This version compiles, but has a lot of bugs.

Working on QGraphicsView-based local waypoints interface supporting drag-and-drop, commented code, fixed Google Maps interface, added mouse and SpinBox zoom to HSIWidget, fixed MAV-based coloring and stylesheets - MEGA COMMIT