WebStyle: better HTTP return statuses 404/500
WebStyle: better HTTP return statuses 404/500

* In mod_python-like legacy publisher implementation, resolve only to
  callable names, otherwise return 404.

* In mod_python-like legacy publisher implementation, alert the admin via
  email about wrong parameters being passed only when CFG_DEVEL_SITE
  is True.

* In case of unexpected error, return HTTP status 500.

* Removed useless call to wsgiref.util.setup_testing_defaults.

inveniosoftware/invenio,tiborsimko/invenio,inveniosoftware/invenio,tiborsimko/invenio