Fix the map editor.

The map editor can now be invoked in ipython:

	import extras.pokemontools.map_editor as ed
	app = ed.init()

Then <app> can be modified on the fly to make up for lacking functionality.
Also see app.map.crop().

Now works with all maps in both Red and Crystal.

The version defaults to Crystal. To use with pokered, invoke from the command line:

	python extras/pokemontools/map_editor.py red

Or in ipython:

	import extras.pokemontools.map_editor as ed
	app = ed.init(version='red')

Connections are WIP.

Also, BSSReader now reads constants and includes, so constant paths are no longer required.