Bug fixes and balls

- Fixed stopping velocity from releasing up/down after getting off of
ladder
- Fixed springs launching different speeds / not launching at all
- Springs now launch Enemy actors (And any other moveable physics actor
locked in the 2d axis)
- Created "Ball" actor which can also kill the enemy (buggy because 2d)
- Destructible platforms now collapse after an actor spends a specific
time on top of it
- Added a new "death" animation for broken ledges
- Overlap methods now work apart from the ladder
- set bounds on map