#675 win32ui crashes on exit with large wx Application

[ANoDE]

Under Windows 8.1 / Python27 64Bit / pywin32 build 219 there seems to be a race condition during the shutdown of the application.

Debugging showed, that some Windows messages are sent AFTER the Python interpreter has already shut down (Py_Finalize already called).

The call to

//win32win.cpp:77 (inside Python_check_message)
CEnterLeavePython _celp;

is therefore working with a dead python instance and crashes.

Suggested fix:
The error can be prevented, if the following code is added to the win32uimodule.cpp file:

static void UnhookWindowsMessages() 
{
    if (hhook)
        UnhookWindowsHookEx(hhook);
    hhook = 0;
}

static void win32ui_finalize (void)
{
  UnhookWindowsMessages();
}

// At the end of PYWIN_MODULE_INIT_FUNC(win32ui):

  Py_AtExit(win32ui_finalize);

Working with Py_AtExit is not always the best choice, but in this case it seems legit.