beamlibrary deregister function

[JamshedVesuna]

Deregister a client app from the node server.

[JamshedVesuna]

Added, lets see if this works

[DepthDeluxe]

I'll add the hooks to do this. I'm thinking the only reason why you would do this is you want to cleanly close the node server. We may also want to have the ability to close the node server and leave the client apps running so that you can reboot or something like that. Once the client apps close, there aren't really any hooks to get it back up and running.