Installed Surge, fixed compile errors, moved a bunch of external stuff into folder

Assets/External/Pixelplacement/Surge/Utilities/LayerMaskHelper.cs

@@ -0,0 +1,56 @@
+/// <summary>
+/// SURGE FRAMEWORK
+/// Author: Bob Berkebile
+/// Email: bobb@pixelplacement.com
+/// 
+/// Helpers for layermasls: http://www.pixelplacement.com/site/2012/01/31/layermasks-simplified/
+/// 
+/// </summary>
+
+using UnityEngine;
+
+namespace Pixelplacement
+{
+    public class LayerMaskHelper
+    {
+        public static int OnlyIncluding(params int[] layers)
+        {
+            return MakeMask(layers);
+        }
+
+        public static int Everything()
+        {
+            return -1;
+        }
+
+        public static int Default()
+        {
+            return 1;
+        }
+
+        public static int Nothing()
+        {
+            return 0;
+        }
+
+        public static int EverythingBut(params int[] layers)
+        {
+            return ~MakeMask(layers);
+        }
+
+        public static bool ContainsLayer(LayerMask layerMask, int layer)
+        {
+            return (layerMask.value & 1 << layer) != 0;
+        }
+
+        static int MakeMask(params int[] layers)
+        {
+            int mask = 0;
+            foreach (int item in layers)
+            {
+                mask |= 1 << item;
+            }
+            return mask;
+        }
+    }
+}