Added level information and reset button.

- Player resets if falls out of screen.
- Level resets if the 'R' key is pressed.
- Levels are slightly customisables using LevelInfo.
Improved colliders and added finish line.

- Colliders for entities can be easily fine tuned with a debug canvas.
- Added new assets for finish line. Also changed some colours.
- Linked win situation to LevelWorld. Need to trigger a load of next
  level.