title: Kivy : Relative size of text displaying in a popup
body: <p>Is there any way to make the message/title in the label fits into the popup ?</p>
  
  <p>'<code>message</code>' or '<code>title</code>' can be a long text that goes beyond the borders of the popup .</p>
  
  <pre><code>   def popup_display(self, title, message):
  
          btnclose = Button(text='Close me', size_hint_y=None, height=50)
  
          content = BoxLayout(orientation='vertical')
          content.add_widget(Label(text=message))
          content.add_widget(btnclose)
  
          popup = Popup(content=content, title=title,
                        size_hint=(None, None), 
                        size=(300, 300),
                        auto_dismiss=False)
  
          btnclose.bind(on_release=popup.dismiss)
  
          popup.open()
  </code></pre>