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
Converted 8-space tabs to 4 spaces.
Inventory now stores a copy of player instead of bouncing the inventory
through State.
Added new items, final game items, boss-ready boolean
Refactoring
Items are now static classes.
Merge branch 'master' into inventory_refactor

Conflicts:
	game/src/gameScreen.py
	game/src/inventoryScreen.py
	game/src/player.py
Fixing broken test
Removed boss sound as member of player class.
Removing item integer types
Merge branch 'master' into knusbaum-items

Conflicts:
	game/src/inventoryScreen.py
	game/src/item.py
	game/src/player.py
	game/src/state.py
	game/src/tile.py
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
Merged with earlier commits
Removed a function from interactiveScreen.py after I realized it was no longer necessary
Going to try to merge again
Changed some key errors