NAME
        SortGList -- Sort the current gel list, ordering its y,x coordinates.
   SYNOPSIS
        SortGList(rp)
                  A1
        void SortGList(struct rastport *);
   FUNCTION
        Sorts the current gel list according to the gels' y,x coordinates.
        This sorting is essential before calls to drawglist or docollision.
   INPUTS
        rp = pointer to the rastport structure containing the gelsinfo
   RESULT
   BUGS
   SEE ALSO
        initgels()  docollision()  drawglist()  graphics/rastport.h