[IMP] web: 'Not Archived' becomes 'Active', 'Not published' becomes 'Unpublished'

Another reason why it’s better to change ‘not archived’ into ‘active’ is
because ‘active’ is the functional name of this field in the filter list in list view.

For the rest, it’s just a better en_US way of saying it.

addons/website_blog/controllers/main.py

@@ -112,7 +112,7 @@ class WebsiteBlog(http.Controller):
          - 'active_tag_ids' :  list of active tag ids,
          - 'tags_list' : function to built the comma-separated tag list ids (for the url),
          - 'tags': all tags, for navigation
-         - 'state_info': state of published/not published filter
+         - 'state_info': state of published/unpublished filter
          - 'nav_list': a dict [year][month] for archives navigation
          - 'date': date_begin optional parameter, used in archives navigation
          - 'blog_url': help object to create URLs