in emqtt_client.c:
-> add test if suback_received_cb is different from NULL
-> get msg->topic_id even if suback_error_cb is NULL

in emqtt_server.c:
-> add return when we match a topic name
fix format
Merge pull request #10 from JulienMasson/master

Handle suback and puback cb if NULL and add return in emqtt_server