dispose of slimdx gamepads on program close

BizHawk.MultiClient/Input/GamePad.cs

@@ -44,6 +44,13 @@ namespace BizHawk.MultiClient
 				device.Update();
 		}
 
+		public static void CloseAll()
+		{
+			foreach (var device in Devices)
+				device.joystick.Dispose();
+			Devices.Clear();
+		}
+
 		// ********************************** Instance Members **********************************
 
 		readonly string name;

BizHawk.MultiClient/Program.cs

@@ -84,6 +84,7 @@ namespace BizHawk.MultiClient
 					Global.DSound.Dispose();
 				if (Global.Direct3D != null && Global.Direct3D.Disposed == false)
 					Global.Direct3D.Dispose();
+				GamePad.CloseAll();
 			}
 #endif
 		}