gzip support

In case of:
XMLRPCClient client = new XMLRPCClient(url));           client.setCustomHttpHeader("Accept-Encoding", "gzip");

in the XMLRPCClient.java should handle it with:

Existing Line #689: istream = http.getInputStream();
if ("gzip".equals(conn.getContentEncoding()))
                    {
                        istream = new GZIPInputStream(istream);
                    }
