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

Finished scaffolding the graphical addition of WP via the MapWidget. Added the possibility to display the latitude and longitude of the cursor as a property of QMapControl. Major reorganization of the MapWidget constructor