Display bug with Roof layer and right walls in Jail map

[ethanmoffat]

Because of how map rendering works, walls can be drawn over the Roof layer:

Map rendering should be changed to use a depth buffer approach instead of trying to draw each entity in the proper order based on the ordering in MapEntityRendererProvider. See: https://github.com/Cirras/eomap-js/blob/3595405bbb5623287a172985467a242ea5f3ce58/src/gameobjects/eomap.js#L10-L26

[ethanmoffat]

Another one for the depth buffer: map objects and walls

[ethanmoffat]

The second example is fixed in #213 (ea19e68) - unfortunately the first example is not.