Zanac Anti-Flash Hack

This is a small patch to the graphics effects that removes the flashing white
light effects that occur when a fortress is destroyed or a screen-clearing
attack like Weapon 6 is deployed. This should make the game more accessible
to photosensitive players or otherwise make the game a bit more safely
livestreamable.

To apply: Simply apply Zanac_Antiflash to a Zanac [USA] image.