Have settings loaded/stored correctly for all joysticks based on their UAS type and autopilot type. Switching between UASes doesn't work right yet, however.

Changed many functions in the abstract *Link classes to be const. This facilitates setting other functions as const. The metadata for specific links are reset when the links are added.

Partway through refactoring of UAS deletion. This is in order to actually support removing UASes from QGC, which is currently impossible.

Changed many functions in the abstract *Link classes to be const. This facilitates setting other functions as const. The metadata for specific links are reset when the links are added.

Partway through refactoring of UAS deletion. This is in order to actually support removing UASes from QGC, which is currently impossible.

Introduced persistence in RGBDview, needs debugging, fixed a bug in param reading in the simulator, pushed message sender a bit forward, not working yet