Service discovery on the LAN on Mira

So I don't have much to show, but here is something...

This means the Mira client application can register its own peer-to-peer service and discover other clients on the network.

There's some more to do before I can actually show some useful screenshots. Mainly re-doing the client networking code. Shouldn't be much work since I'm just going to use the Server's network code as a template. Like I did before, but this time taking into account the fact that the client is somewhat of a server as well.

By the way, this only works on linux so far. I plan to do a version using Bonjour so it'll work on windows and Mac OS X. So for now I'll be posting to a separate branch.