tasks.
Created a tile load queue. When we init, or cross a tile boundary, we
stuff the new tiles to be loaded on a load queue, and then only load
one tile per frame. This will need further refinement, but it is better
than what we had.
GUI improvements contributed by Norman Vine.
3dfx.sh wrapper script now sets voodoo2 variables as well.
Start of support for user defined texture scale.
Start of support for precalculated texture coordinates.
