Import of gimp-dds to pkgsrc-wip.

GIMP plugin that allows you to load and save images in the Direct Draw
Surface (DDS) format.

Features:
    Load/save DDS files, optionally using DirectX texture compression (DXT)
    Optional automatic mipmap generation when saving
    Load mipmaps into separate layers
    Load cube map faces and volume map slices into separate layers
    Save cube maps and volume maps with automatic mipmap generation support
    Save image with a custom pixel format
    Non-power-of-two image loading and saving support with automatic
     mipmap generation support
    Compliant with DirectX 10 block compressed (BC) formats
+gimp-dds