XNA physics testbed, just 2 cubes for now, move with a/d keys

Extras/XNAPhysics/Physics/Program.cs

@@ -0,0 +1,19 @@
+using System;
+
+namespace Physics
+{
+    static class Program
+    {
+        /// <summary>
+        /// The main entry point for the application.
+        /// </summary>
+        static void Main(string[] args)
+        {
+            using (Game1 game = new Game1())
+            {
+                game.Run();
+            }
+        }
+    }
+}
+