This branch changes the LAN plugin's port selection behaviour so it chooses a preferred port number in advance and shares the port number with contacts. This allows contacts to connect in the following scenario:
The preferred port is also used when connecting to new wifi networks. For wifi networks we've previously connected to, we continue to use the same port as before, so this branch shouldn't harm connectivity between existing contacts, including those where one has upgraded to this branch and the other hasn't.
Closes #1328 (closed)