Bug fixes, optimizations

- Made game loop constants such as the target FPS, target TPS, and max
updates before render editable from the r2dgame
- Fixed a bug where no entities were interpolating their position on
render, effectively capping the FPS at 30 (I’m an idiot)
- Fixed a bug where in certain situations editing the entity list while
ticking an entity in the list skips an entity when the iterator moves
on to the next entity to tick
- Removed obsolete functions in Map.java
- Added a fast collision check function in Map.java, collidesWithMap()