- Move all map rendering to a new MapWindow class
- Clip map rendering to the bounds of the Window
- Pass in Entities list from the Engine and render them relative to the window
The map doesn't scroll yet, so it'll always be clipped on the bottom and
right.
It renders a bar of a certain width and a percentage full. Use it to render HP.
Add a new Python package called interface. The Bar class lives there. Also add a
bunch of color defintions to a module called interface.color.
