Added a config.txt option to manually designate a server address, as the current world.address method doesn't work right.

Fixed a runtime error I noticed in login.dm

git-svn-id: http://tgstation13.googlecode.com/svn/trunk@100 316c924e-a436-60f5-8080-3fe189b3f50e

code/datums/configuration.dm

@@ -31,6 +31,8 @@
 	var/hostedby = null
 	var/respawn = 1
 
+	var/server
+
 /datum/configuration/New()
 	var/list/L = typesof(/datum/game_mode) - /datum/game_mode
 	for (var/T in L)
@@ -156,6 +158,9 @@
 			if ("hostedby")
 				config.hostedby = value
 
+			if ("server")
+				config.server = value
+
 			if ("probability")
 				var/prob_pos = findtext(value, " ")
 				var/prob_name = null