- fix launching obfs3_flashproxy
Modified pt_launch_pair into pt_launch_chain. The new method of chaining starts with the last socks server pointing to the last pt with the destination being the bridge server. Then the middle pts are chained in reverse order. Finally the first socks server is started at the callback port and links to the second pt. The helper function pt_setup_socks_proxy takes care of setting up a specific SOCKS server.