Add MqttClient#unsubscribe
Refactor Connection#connack error handling
Refactor generate#publish
Refactor generate#connack
Refactored Generate#subscribe
Refactored generate#suback
Trim
Refactored generate#unsubscribe
Refactor net connect out of MqttClient constructor
Ping every <keepalive>ms
Remove stream event echoing from Connection
Tidy lib/connection
Change MqttClient#ping from setTimeout to setInterval
Refactored lib/mqtt
Remove tcp specifics from lib/client
lib/mqtt docs
Add mqtt#createConnection

Replacement for the old mqtt#createClient
Update test path
Park old tests
Wrap server Connections in MqttServerClients