[web] put a fake object that raise Unauthorized on any attribute access as req.cnx and req._user, so we are properly asked to authenticated on any view that tries to do something with one of those attributes (instead of doing defensive programming everywhere we're doing that)

[etwist] we must call all error not handled in _render_request, else the thread fail silently and nothing ends up on the ui

backport stable

[test] fix unittest_viewselector

[tests] fix bfss tests to match new uniquify implementation

[schema view] the final touch. Things are getting nicely displayed, and code clean

backport stable