Upgrade to roundup 2.0
We need to update roundup to run on Python3. The support for Python3 is urgent as the Gentoo OS is removing Python2 support.
I think we should take the chance to change the template from classic to jinja2. The advantages are:
* responsive (#9066 (closed))
* markdown editor for message (formatting, link, image etc.)
* jinja2 as template language instead of zopetal
* Bootstrap (we could reuse the www.tryton.org CSS)
The disadvantage are:
* no classhelp (popup to select multilink value)
I think it worth the lost. As the feature was not very good with large values like users or components. The keywords is a little bit annoying. Maybe someone could contribute to roundup-tracker.org a solution maybe based on BS dropdown and some JS.
PS: For those who have access, I already updated https://bugs.b2ck.com/ to this template.