Add Catseye ball
Add blue-green catseye ball variant from https://github.com/Cheeseness/neverball-ball-extras/
catseye-surface and catseye-surface.png are copies of snowglobe assets and could benefit from being abstracted away to some shared materials folder.

Add internal bubbles to catseye ball.

Added backface drawing to catseye ball
Merge pull request #65 from Cheeseness/master

Add Catseye ball