Add the ability to specify hub ip addresses in Hub Mesh

[bertabcd1234]

You could see if this endpoint to set Hub Mesh peers works:

Hub mesh wrong IP

There's an endpoint to set initial hub mesh peers. Now that the issue surfaced again, I'll probably add the to the UI as well. http://hubs.ip.address.here/hub/advanced/setInitialHubMeshPeers?192.168.1.2,192.168.1.3, with comma separated IP address list as a query string. It should say "done" when list is updated. The list takes effect when hub mesh is restarted next time. http://hubs.ip.address.here/hub/advanced/setInitialHubMeshPeers?none resets the list. http://hubs.ip.address.here/hub/adv…

However, if the two subnets aren't in the same broadcast domain (and they might not be if discovery isn't working in the first place), I'm not sure that Hub Mesh would work either way.