suggest: use ZMQ_SNDZMQ for zmq >= 3
suggest: use ZMQ_SNDZMQ for zmq >= 3

GitHub: fixes #63

See also: http://www.zeromq.org/docs:3-1-upgrade

Reported by Naoya Inada. Thanks!!!

    groonga_suggest_httpd.c: In function ‘serve_threads’:
    groonga_suggest_httpd.c:596:51: error: ‘ZMQ_HWM’ undeclared (first use in this function)
                   zmq_setsockopt(threads[i].zmq_sock, ZMQ_HWM, &hwm, sizeof(uint64_t));
                                                       ^

hiroyuki-sato/groonga,kenhys/groonga,myokoym/groonga,myokoym/groonga,cosmo0920/groonga,naoa/groonga,myokoym/groonga,naoa/groonga,cosmo0920/groonga,groonga/groonga,hiroyuki-sato/groonga,groonga/groonga,cosmo0920/groonga,komainu8/groonga,kenhys/groonga,kenhys/groonga,redfigure/groonga,redfigure/groonga,cosmo0920/groonga,hiroyuki-sato/groonga,komainu8/groonga,kenhys/groonga,komainu8/groonga,redfigure/groonga,naoa/groonga,cosmo0920/groonga,kenhys/groonga,myokoym/groonga,groonga/groonga,groonga/groonga,hiroyuki-sato/groonga,myokoym/groonga,redfigure/groonga,naoa/groonga,redfigure/groonga,myokoym/groonga,komainu8/groonga,groonga/groonga,redfigure/groonga,komainu8/groonga,naoa/groonga,myokoym/groonga,kenhys/groonga,groonga/groonga,groonga/groonga,naoa/groonga,cosmo0920/groonga,redfigure/groonga,naoa/groonga,komainu8/groonga,hiroyuki-sato/groonga,redfigure/groonga,hiroyuki-sato/groonga,cosmo0920/groonga,hiroyuki-sato/groonga,komainu8/groonga,groonga/groonga,kenhys/groonga,kenhys/groonga,komainu8/groonga,cosmo0920/groonga,hiroyuki-sato/groonga,naoa/groonga,myokoym/groonga