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/Items/CharacterInventory.cs

@@ -0,0 +1,20 @@
+using System;
+using System.Linq;
+using Microsoft.Xna.Framework;
+using Microsoft.Xna.Framework.Graphics;
+using Microsoft.Xna.Framework.Input;
+using Barotrauma.Networking;
+using Lidgren.Network;
+using System.Collections.Generic;
+using Barotrauma.Items.Components;
+
+namespace Barotrauma
+{
+    partial class CharacterInventory : Inventory
+    {
+        void InitProjSpecific()
+        {
+            //do nothing
+        }
+    }
+}