More experiments with level loading

- Added more enemies (and added a test to the world)
- Added new (crap) sprites
- Updated one tonne of feathers
- Deleted multi-circle, since there is an upgraded version in
bosspatterns
- Added test for compiling levels in base64 format, to deter cheaters
from editing the level source, you can still do it, but its much more of
a hassle, and you would have to encode it properly again.
- Fixed spawner code in level loader not working
- Added new upa parser.-