TownSnapshot

The big thing I did today was to get town snapshots working. Basically the thing I talked about yesterday. There's now an EnterTownRequest object, and when it goes through, the server caches the state of the town's market off on the PlayerSession (this is all a bit of a puppet show, because there's no time-variability in prices yet).

I also stubbed out the cvclient dll. For a long time I wasn't even sure I'd need one, since the interactions on the client with game state didn't seem too rich (rather, the unique, clienty bits). But I eventually talked myself into it. I think it might be a good design goal of the Unity visualization layer wasn't even allowed access to the shared-dll namespace (even though of course it's linking the shared dll). That would be some good concept-isolation between the game and the visualizer, if it could be done.