Minor changes

- Added additional collision checking for the snake object: can no
longer intersect with itself. Loss of life on body collision pending.
- Changed the room dimensions from 1280x720. For now. Still need to see
the orientation of the arcade cabinet's monitor before making room size
final calls.
- Added regaining body length by cannibalizing yourself, with a 50%
regeneration rate as requested.
- Added a motorcycle object. Wraparound behavior is not working as
intended; do not implement it yet.
- More code fixes and optimizations. Snake body part immunity has been
reduced to 1/60th of a second, allowing for more simultaneous collisions
and reducing likelihood of odd behavior with really really long snakes.