tielset attributes file

[Zallus]

There should be a human-readable file one can create to use with custom tilesets, that allows for custom placements of tile-types. e.g.
(0 = Water,
1 = Grass,
2 = Dirt,
3 = Lava,)

11110111011
00111111011
01111011001
10122111222
21111122122
22210102120
22211022213 etc...

It would greatly expand the use of tilesets if we could just issue a command like addtiledef imagefile,textfile,levels;