Handling socket read requests that return Connection Refused

I've modified my local copy of steam-condenser to more gracefully handle socket read commands that return refused connections.

A summary of my changes:

Socket class updated to throw an Exception with an error code in Socket::recv() if socket_read() returns Connection Refused.

SteamSocket class updated to check Exceptions for the Connection
Refused error code in SteamSocket:receivePacket().

GameServer class updated to have GameServer::updatePing() call
itself recursively if a general Exception was caught, but will
stop calling itself and rethrow a TimeoutException.