Redirections should apply to any view with slug

[mgaitan]

currently only detail handle redirections, prepending a code like this

    # handle redirects first
    try:
        redirect = Redirect.objects.get(old_slug=slug)      # noqa
        if redirect.status_code == 302:
            return HttpResponseRedirect(redirect.get_absolute_url())
        return HttpResponsePermanentRedirect(redirect.get_absolute_url())
    except Redirect.DoesNotExist:
        pass

this should be a decorator applied to every view based on the "slug" pattern.

So, for example, if there is a redirection from 'slug' to 'new-slug', any of this should work:

• ../slug/raw -> ../new-slug/raw
• ../slug/edit -> `../new-slug/edit
• ../slug/version/X -> ../new-slug/version/X

and so on