RENAME ‘emqtt’ to ‘emqttd’!

Support [Broker Bridge]() Now!

Change: rename project from ‘emqtt’ to ‘emqttd’

Feature: emqttd_bridge, emqttd_bridge_sup to support broker bridge

Feature: emqtt_event to publish client connected/disconnected message to $SYS topics

Feature: ./bin/emqttd_ctl add more commands: listeners, broker, bridges, start_bridge, stop_bridge…

Feature: issue#68 - if sys_interval = 0, emqttd_broker will not publish messages to $SYS/brokers/#

Bugfix: issue#67 - subscribe ‘#’ to receive all messages

Bugfix: issue#64 - emqtt_app start/2: should wait_for_databases