def new_stat(self):
        """Look at the key and value that the user has entered into the stat
        configurator, and set them on the currently selected
        entity.

        """
        key = self.ids.newstatkey.text
        value = self.ids.newstatval.text
        if not (key and value):
            # TODO implement some feedback to the effect that
            # you need to enter things
            return
        try:
            self.proxy[key] = self.engine.unpack(value)
        except (TypeError, ValueError):
            self.proxy[key] = value
        self.ids.newstatkey.text = ''
        self.ids.newstatval.text = ''
Look at the key and value that the user has entered into the stat
        configurator, and set them on the currently selected
        entity.