Effects have direct accesses to the effected.

Docstring had the target of the effect as an int; is now the Actor itself,
rather than its id.
Updated some tests so they complete.

Some tests were throwing exceptions. Fixed so that they're in line with
newer strucutre and fail instead of erroring out.:x
Commands now execute immediately.
Modified Camera, LevelView to bar direct access.

Previously, Camera had direct access to player_actor through LevelView;
wrote pass-through functions in LevelView to rectify the situation.
Fixed player_actor load, added get_all_entities()

player_actor was not being assigned correctly; fixed. Also, there is now a
Level.get_all_entities() function.
Updated Enrage, Adversary's select_target function.
Implemented a selection of commands.

Implemented some of the Commands. Added helper functions in Level to
assist in the implementation.

Commands implemented:
	CellSetPassable
	LevelRemoveEntity (added Level.remove_entity(eid))
	LevelMoveEntity
	EntityUseMoves (uses Level.get_entity_by_id(eid))