Add specific support for class_, class__ to html_params, to play nice with mako and genshi. These will strip the final underscore in the output, so class_ becomes class and class__ becomes class_.
Add specific support for class_, class__ to html_params, to play nice with mako and genshi. These will strip the final underscore in the output, so class_ becomes class and class__ becomes class_.

Khan/wtforms,mobyle2-legacy/WTForms,mobyle2-legacy/WTForms