SelectField option_widget argument not used

[nathan-steyer]

The option_widget parameter to SelectField is not used by the built-in Select widget to render the choices as option elements. It appears to use its render_option class method regardless.

[ftm]

If nothing uses it, I think the option_widget parameter should be removed as unless I'm mistaken there's nothing else you can use other than <option> which is the default.

[davidism]

It's definitely used elsewhere. See RadioField for an example:

class RadioField(SelectField):
    widget = widgets.ListWidget(prefix_label=False)
    option_widget = widgets.RadioInput()

SelectField could use some cleanup, it's a bit circuitous right now.