SupCom-style zoom tilting option for COFC

This adds a (default-off) option to make the camera tilt on zoom, much like most RTS games. I think it would help new players feel more at home with the camera were it made default, and it makes viewing one's army while zooming in easier, as one doesn't need to rotate the camera manually to avoid starting at a tiny patch of ground.

Some known issues are that, due to the way the smoothness is handled, the camera seems to finish changing its y value last, so this can occasionally cause the target location to drift.

Also, a suggestion for defaults: Zoom out to center and Tilt Camera while Zooming on (for Zooming section), and everything else unchanged.