Improve netconf performance: keep the control socket connection open
In 1.5 the kea-netconf agent opens up a new connection every time there is a new config to be set. This means that if you're changing the configuration frequently, there are many connections set up and torn down. It would be better to have persistent connection (or the option to enable it).
This is out of scope for 1.5, though. Looks like a potential optimization in 1.6.