title: Iterating over controls in wxPython in order to save session data
body: <p>I have a GUI written in wxPython (with boa constructor). 
  I would like to save a user's session to a file, to be loaded the next time the application starts. 
  I would like to avoid saving each value 'by hand' by iterating over the controls and saving their values to a dictionary. </p>
  
  <p>Is there a way to get a hold of all the wxIDs used in the application, and their corresponding widgets?</p>