Enhance the emqttd_ctl module to allow plugins to register new commands (#256)

Add [emqttd_recon plugin]() to debug/optimize the broker (#235)

Add ‘./bin/emqttd_ctl broker pubsub’ command to check the status of core pubsub processes

Add ‘./bin/emqttd_top’ command(like etop) to show the top ‘msg_q’, ‘reductions’, ‘memory’ or ‘runtime’ processes

‘rel/files/emqttd.config.development’ for development deployment

Qos1/2 messages will not be dropped under unstable mobile network (#264)

emqttd_, emqttd_ APIs should be asynchronous (#292)

etc/emqttd.config: ‘idle_timeout’ option to close the idle client(socket connected but no ‘CONNECT’ frame received)

How to monitor large ‘message_queue_len’ (#283)

Behaviour emqttd_auth_mod is missing init callback (#318)

Write a new [benchmark tool](https://github.com/emqtt/emqtt_benchmark) to benchmark this release

Hw requirements - 5K users, 25-50 msgs/sec, QoS=1 (#209)