Removed OpenGL dependency in HUD, merged in HUD from Soren Kuula and config changes from Michael Carpenter

Impl. Lorenz suggestions wrt one velocityChanged, altitudeChanged, speedChanged signal per reference frame. Impl. CDI on compass disk.

Change so MainWindow handles its own deletion, and deletion of other UI objects to allow for closing when the MainWindow is closed, regardless of if other windows are open.

Change for the new RC calibration widget, still needs an if/else to load the old one for unsupported systems

Changes go UASQuickView handles resizing better, and doesn't "clip" text when the window is too small.

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