Fixed many slime bugs.

- Fixed slime hurt/death sound
- Added slime spawning on death
- Fixed the max health
- Fixed the attack damage
- Little slimes should not attack players (fixes #1202)
I do believe it's correct here. `i % 2` flips between 0 and 1, subtract 0.5 and you have a number toggling between -0.5 and 0.5