Setup portal_language correctly

When installing a Plone site with the default add-site view, the language
is set in the ``Products.CMFPlone:plone-content``, which also creates example content.
This makes it hard to not create example content but setup the language correctly.

To solve this issue ``ftw.inflator`` provides a ``ftw.inflator:setup-language`` generic
setup profile, meant to be used while setting up a bundle.
You can add it to the list of bundle profiles.
Using it as a dependency (in ``metadata.xml``) is not recommended, since it is not meant
to be used on a existing plone site.