Fixed visibility checking to be much more reliable.
Added markers to visibility checking.
Added QuaternionToFocus util.
Added conversion methods to utils.
Change MakeCameraMarker's signature and access.
Made autocp offer clickable viewpoint suggestions.
Eliminated features that don't make sense in the clickable interactive marker setting.
Merge branch 'clickable' of github.com:jstnhuang/autocp into clickable