Did some minor Vector optimization.

src/com/sk89q/worldedit/Vector.java

@@ -446,6 +446,18 @@ public class Vector {
                 Math.pow(pt.z - z, 2));
     }
 
+    /**
+     * Get the distance away from a point, squared.
+     *
+     * @param pt
+     * @return distance
+     */
+    public double distanceSq(Vector pt) {
+        return Math.pow(pt.x - x, 2) +
+                Math.pow(pt.y - y, 2) +
+                Math.pow(pt.z - z, 2);
+    }
+
     /**
      * Checks to see if a vector is contained with another.
      *