Added --quit-at-step
Added --show-grid
Added some maze info
Refactor: don't reset steps upon Test::move
Test: cornering movement
Test: pacman has only 1 life
Changed test todos
Refactor: added DefaultGameObserver
Refactor: used DefaultGameObserver in Test
Refactor: renamed Test to MovementTest
Test: Eat 1 energizer, remain vulnerable for exactly 6 seconds