- make GRFMerge aware of DOS/Win difference: trg1 vs. trg1r
- build DOS/Win maps in GRFMerge
- make .nfo pseudo-sprite format more versatile:
  * no lengths, instead line-continuation with backslash-cr or backslash-lf
  * allow hex, dec, oct postfixes like assembly (40, 24d...), default hex
  * allow byte, word, dword and string values (W:4, D:60d, "Hello there")
