Option to export Wolf3D-Engine game graphics as 64x64 with proper offsets.

[PerdGateEnjoyer]

When I extract something from Wolfenstein 3D, it cannot be automatically centered by the tools I use (due to the baked-in shadow). Wolf3D-specific editors (like ChaosEdit) allow for graphics to be ripped in 64x64 with proper centering, but batch-exporting is slow and it can only export graphics as .bmp files.