win32: make F10 key not enter the window menu

Normally, F10 enters the window menu (it's invisible at first, and the
blocking/recursive message handling by Windows makes it look like
mplayer was paused, without much visual indication). Stop this almost
completely useless behavior by signalling Windows that the F10 key was
handled. This makes the F10 key usable as normal mplayer shortcut.

This is probably still somewhat questionable.

libvo/w32_common.c

@@ -211,6 +211,8 @@ static LRESULT CALLBACK WndProc(HWND hWnd, UINT message, WPARAM wParam, LPARAM l
             int mpkey = lookup_keymap_table(vk_map, wParam);
             if (mpkey)
                 mplayer_put_key(mpkey | mod_state());
+            if (wParam == VK_F10)
+                return 0;
             break;
         }
         case WM_KEYUP: