Data Types: Byte
    Color Spaces: MAP only, (Gray and Binary saved as MAP)
    Compressions: 
      LZW - Lempel-Ziv & Welch      [default]
    Can have more than one image.
    No alpha channel.
    Internally the lines are arranged from top down to bottom.
    Handle() returns a imBinFile* pointer.
 
    Attributes:
      ScreenHeight, ScreenWidth IM_USHORT (1) screen size [default to the first image size]
      Interlaced IM_INT (1 | 0) default 0 
      Description (string)
      TransparencyIndex IM_BYTE (1)
      XScreen, YScreen IM_USHORT (1) screen position
      UserInput IM_BYTE (1) [1, 0]
      Disposal (string) [UNDEF, LEAVE, RBACK, RPREV]
      Delay IM_USHORT (1)
      Iterations IM_USHORT (1) (NETSCAPE2.0 Application Extension)

    Comments:
      Attributes after the last image are ignored.
      Reads GIF87 and GIF89, but writes GIF89 always.
      Ignored attributes: Background Color Index, Pixel Aspect Ratio, 
                          Plain Text Extensions, Application Extensions...