Remove old notes file.
Remove state from Player.
Refactoring lesson definition.
Remove unneeded attribute.
Fix bug left over from refactoring.
Don't walk down the stairs if the level isn't complete.
Fix stair-detection code.
Fix regression with attacking enemies.
Don't rest if the level is clear already.
Fix bug with neighbor enemy detection code.
Attack bound enemies if there is no ticking and health is full.
Update profile - score 911.