libgdgeda is a special version of gd 1.6, specifically created for
gEDA.  The changes from the original gd library are:

    - gdImageArc arcs rotate counterclockwise (as opposed to the
      original clockwise rotation).
    - mtables.c is now build like any other C file (ie it's not
      #included).  Created mtables.h which contain the prototypes
      for the math lookup tables.
    - Created libgdgeda-config, which is a sh script.  This script
      is used in gEDA to determine the various build parameters of
      libgdgeda (cflags and ldflags).
    - index.html was moved into the doc directory
    - Updated source from gd 1.6 which removes support for gifs and
      adds support for pngs.  Now requires libpng.
    - Updated source from gd 1.6.3
    - Updated to libtool 1.3.3

  It is recommended that people wanting to use gd in their own
programs use the original gd (unless you happen to need some of the
modifications that were made).