Update for integer changes
Add keyboard input
Allow the player to rotate in two directions
Rotate tetrominoes around their center
Spawn sets of shuffled tetrominoes
Instead of picking the next one randomly every time.
Implement game over state
Initial work on line clearing
canmove: fix collision bug above y=0
Check collisions on rotation attempts
Refactor collision detection
update.ha: remove unused import
Fix L tetromino rotations
Partially implement rotation
Still missing a test to make sure the next state will fit.
Prevent same color from being used twice