Game now reads map state from a current_game directory.

Part of #23
Began adding to_json and from_json functions for use in saving

Part of #23
Tile now writes to *.json when you leave a file. This way, destroyed
enemyies do not respawn.

Part of #23

TODO: add support for crates
Merge branch 'master' into saving

Conflicts:
	game/src/creature.py
	game/src/gameScreen.py
	game/src/player.py
	game/src/tile.py
Split maps and saves into separate directories
Game can now be saved and restored.

Final part of #23
Changed some key errors
"Quick fix for a bug (needs to be investigated further"