Substantially bugfixed and improved deactivation/activation and persistence of widgets. A lot of testing of Google Earth view, only minor improvements

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

Improved runtime performance, currently hunting down a bug where the whole application gets repainted although only parts of it are refreshed