Log Message:
net: Add mosquitto 1.6.3nb4

(nb4 because wip is nb4)

Eclipse Mosquitto is an open source (EPL/EDL licensed) message broker that
implements the MQTT protocol versions 3.1 and 3.1.1 MQTT provides a
lightweight method of carrying out messaging using a publish/subscribe model.
This makes it suitable for "Internet of Things" messaging such as with \ 
low power
sensors or mobile devices such as phones, embedded computers or
microcontrollers like the Arduino.