List enumerated joysticks in terminal output.

gtk/src/gtk_control.cpp

@@ -463,6 +463,13 @@ JoyDevice::JoyDevice (unsigned int device_num)
         calibration[i].center = 0;
     }
 
+    printf ("Joystick %d, %s:\n  %d axes, %d buttons, %d hats\n",
+            device_num + 1,
+            SDL_JoystickName (filedes),
+            SDL_JoystickNumButtons (filedes),
+            num_axes,
+            num_hats);
+
     memset (axis, 0, sizeof (int) * num_axes);
 
     return;