make `Location` immutable
normalize access modifiers
REFACTOR: Introduce MoveBy a delta
REFACTOR: Use `MoveBy`
REFACTOR: 1 class per files
REFACTOR: `Matrix<T>` for game board.
REFACTOR: Index in to `Matrix<T>` with `Location`
a static image
Add colors for blank and bigdot.
keyboard input
ghosts move on a timer
report win/lose
use a string to draw the map
bigger board
bigger
Merge branch 'GUI'

* GUI:
  bigger
  bigger board
  use a string to draw the map
  report win/lose
  ghosts move on a timer
  keyboard input
  Add colors for blank and bigdot.
  a static image