Spawn Points (.spawn)
Spawn data of a town is stored in ./iso/towns/<id>.spawn
(SpawnFormat=spawn in iso.ini).
The file is an array of uint32 values that decode as pairs and appear to be
grouped into sections, similar to the nodes file:
| 00 01 02 03 04 05 06 07 |
00000000 | A | B | A | B |
The first value of each pair (A) lies in the tile-column range (0..127),
while the paired value (B) increases monotonically within a run. The exact
field semantics and section boundaries have not been identified.