Small usability fixes for the Google Earth view, is now more convenient to use. Editing now only possible in edit mode, prevents false edits

Improved Google Earth interface, clearing trails works, switching views works (but is not yet perfect), switching editing mode on/off works

Fully working waypoint interface, thoroughly tested. Active waypoint setting has to be debugged in the simulator, but works fine on real hardware

Added new options for windows serial port, fixed a number of bugs, added customizing options to instrument widgets