Added Lan alternative to Steam networking.

[SordX]

Created an option to use a lan connection instead of going through steam. The lan vs steam is configured using a file in the mod folder (see lanconfig.example.txt) and you can switch back and forth as long as you restart the game after changing the file. Defaults to steam if you don't create the config file and should not effect anyone not trying to use it.

I did not unwind all the steam code, so it probably still requires the steam client be installed, but you can play in offline mode as it never connects to the steam servers.

I originally started this as way to bypass the 10 MB save file restriction (which it does do as the lan code has no transfer size limit). It may also transfer the save file faster if you have slow internet (my upload speed is slow).