Always use TCP connection when connecting to self-hosted lobby room.
Effectively reverts 1.6.6 change for lobby connections. Single-player
connections still use intra-process pseudo connection
Main problem is various side effects caused by changing order of
operations. For example, client may inform lobby about joining the room
before server finishes startup, which was not possible before.
This removes need for TCP network connection in single-player games.
Instead, game will now create internal pseudo-connection that performs
client<->server communication by posting sent messages to client/server
asio::io_service'a.
This should fix gameplay aborting on switching to another app on iOS (and
apparently, on Android in some cases)
