This not only simplifies all the use of _t types to the
ScummVM equivalents, it gets rid of the int32 usage in
favor of just int, solving common type clashes with the
Amiga, for which int doesn't match int32
This fixes a crash at the very startup of The Blackwell Legacy,
which reads from a file prog.bwl in the game folder, and then
writes out a new version. In the new scheme, all data files
will try to be accessed from the save folder first, and then
fall back on the game folder. So this allows Blackwell to first
read from the game folder prog.bwl, then create it's own
Paul Gilbert
Cameron Cawley