The tile images must be 64x64. Tiles used in the OBJECT and TOPLEVEL layers
will be loaded and drawn with transparency, ie using masks of xpm None values.

The entity images are a composite image of the directions and frames of the
entities. This speeds up load times drastically. The form of the composite
image is as follows:

	   <- Frames ->

	|----|----|----|-	D
	| A0 | A1 | A2 |	I
	|    |    |    |	R
	|----|----|----|-	E
	| B0 | B1 | B2 |	C
	|    |    |    |	T
	|----|----|----|-	I
	| C0 | C1 | C2 |	O
	|    |    |    |	N
	|----|----|----|-
	|    |    |    |

Where A, B, C are directions and 0,1,2 are frames.

There are 256 directions, so if the image has 8 directions, each would be
rotated 256/8 = 32 degrees clockwises to the above frames. Thus the image for
the first frame of animation in order 1 2 1 2 of 1/4 rotation clockwise with 8
directions would be (256/4) / (256/8) = 2 = C. The first frame is 1, so the
image would be in the above diagram C1.

Frame order is set in the entity configuration file. Frame 0 is used to indicate
a stationary entity, unless stationary_ani is set, in which case the frame order
is used. Thus there is a maximum of 5 frames, with 4 in frame order animation
and one for use while stationary. The maximum number of directions is 256, the
minimum for both frames and directions is one.
