Support latest terrain changes with 64 tilesets

[tdauth]

https://us.forums.blizzard.com/en/warcraft3/t/patch-203-build-23101-is-now-live

Increased the Tileset limit from 16 to 64.

Please note that using more tileset textures may significantly increase the load time of the map. Use with caution!
This change increases the version number of the .w3e file. Saving a map with this version of the editor will make the map incompatible with older versions.