Merge pull request #65 from MOARdV/master

Weekend update
Stitching in...
A method to get at the other handlers.

Which should be handy.
Closes #60
Improvements to JSIOrbitDisplay.

Slight improvements to the automatic scaling, so targets in the same SoI are drawn, even if their orbits aren't.
Always try to draw the target position @ closest approach.
Merge remote-tracking branch 'upstream/master'