Fixed possible memoryleak in loopmanager

Artemis/Artemis/Managers/LoopManager.cs

@@ -144,7 +144,9 @@ namespace Artemis.Managers
                     return;
 
                 // Fill the bitmap's background with black to avoid trailing colors on some keyboards
-                var fixedBmp = new Bitmap(bitmap.Width, bitmap.Height);
+                // Bitmaps needs to be disposd!
+                using (var fixedBmp = new Bitmap(bitmap.Width, bitmap.Height))
+                {
                     using (var g = Graphics.FromImage(fixedBmp))
                     {
                         g.Clear(Color.Black);
@@ -159,3 +161,4 @@ namespace Artemis.Managers
             }
         }
     }
+}