Further separation of client-specific code

Still not done here, just gonna push a commit now so I can pull this from elsewhere.

BarotraumaServer/Source/GameMain.cs

@@ -11,25 +11,69 @@ namespace Barotrauma
 {
     class GameMain
     {
+        public static readonly Version Version = Assembly.GetEntryAssembly().GetName().Version;
+
         public static World World;
+        public static GameSettings Config;
 
         public static GameServer Server;
-
-        public static GameSession GameSession;
-
-        public static GameClient Client
-        {
-            get { return null; }
-        }
-
+        public const GameClient Client = null;
         public static NetworkMember NetworkMember
         {
             get { return Server as NetworkMember; }
         }
 
-        public static Screen EditMapScreen
+        public static GameSession GameSession;
+
+        public static GameMain Instance
         {
-            get { return null; }
+            get;
+            private set;
+        }
+
+        //only screens the server implements
+        public static GameScreen GameScreen;
+        public static NetLobbyScreen NetLobbyScreen;
+
+        //null screens because they are not implemented by the server,
+        //but they're checked for all over the place
+        //TODO: maybe clean up instead of having these constants
+        public const Screen MainMenuScreen = null;
+        public const Screen LobbyScreen = null;
+
+        public const Screen ServerListScreen = null;
+
+        public const Screen EditMapScreen = null;
+        public const Screen EditCharacterScreen = null;
+
+        //
+
+        public static ContentPackage SelectedPackage
+        {
+            get { return Config.SelectedContentPackage; }
+        }
+
+        public GameMain()
+        {
+            Instance = this;
+
+            Config = new GameSettings("serverconfig.xml");
+            if (Config.WasGameUpdated)
+            {
+                UpdaterUtil.CleanOldFiles();
+                Config.WasGameUpdated = false;
+                Config.Save("serverconfig.xml");
+            }
+        }
+
+        public void Run()
+        {
+            //TODO: implement
+        }
+
+        public CoroutineHandle ShowLoading(IEnumerable<object> loader, bool waitKeyHit = true)
+        {
+            return CoroutineManager.StartCoroutine(loader);
         }
     }
 }