Updated logging to use slf4j and log4j

See koraktor/steam-condenser#182
Merge branch 'issue-182' of github.com:snkinard/steam-condenser-java into issue-182

Conflicts:
	src/main/java/com/github/koraktor/steamcondenser/steam/servers/GameServer.java
	src/main/java/com/github/koraktor/steamcondenser/steam/servers/MasterServer.java
	src/main/java/com/github/koraktor/steamcondenser/steam/sockets/GoldSrcSocket.java
	src/main/java/com/github/koraktor/steamcondenser/steam/sockets/MasterServerSocket.java
	src/main/java/com/github/koraktor/steamcondenser/steam/sockets/QuerySocket.java
	src/main/java/com/github/koraktor/steamcondenser/steam/sockets/SourceSocket.java
	src/main/resources/log4j.properties