Crash when trying to load Hellfire nlevels/towndata/town.cel

[AJenbo]

Issue was introduced in a515972

With out investigating I'm thinking this is caused by Hellfire not updating the town metadata but extending the number of tiles so there is some soft of mismatch that we should be tolerant of.

[AJenbo]

Looks like the error is in reading data past the end of the buffer:
https://github.com/savagesteel/d1-graphics-tool/blob/master/source/d1celtilesetframe.cpp#L48

If guarding against that we can open the file, but the last 3 subtiles are missing:

[AJenbo]

Frames past 3794 are decoded using the wrong type:

[AJenbo]

The issue turned out to be Hellfire's town.sol only having 1376 tiles instead of 1379