Print a summary about the GAF file that was read.

def prt_error_summary(self, fout_err):
        """Print a summary about the GAF file that was read."""
        # Get summary of error types and their counts
        errcnts = []
        if self.ignored:
            errcnts.append("  {N:9,} IGNORED associations\n".format(N=len(self.ignored)))
        if self.illegal_lines:
            for err_name, errors in self.illegal_lines.items():
                errcnts.append("  {N:9,} {ERROR}\n".format(N=len(errors), ERROR=err_name))
        # Save error details into a log file
        fout_log = self._wrlog_details_illegal_gaf(fout_err, errcnts)
        sys.stdout.write("  WROTE GAF ERROR LOG: {LOG}:\n".format(LOG=fout_log))
        for err_cnt in errcnts:
            sys.stdout.write(err_cnt)