WebSearch: faceted results order fix
WebSearch: faceted results order fix

* Quickly fixes order of faceted search results.  (addresses #1352)

* Improves speed of loading websearch blueprint by moving facet plugins
  discovery to before_first_app_request handler.

* TODO improve perform_request_search to return intbitset with results
  and eventually raise exception when nothing is found with near search
  terms.

Signed-off-by: Jiri Kuncar <2bdffcb416fed3002465740d19a053a39918cbe5@cern.ch>

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