WebSearch: configurable display of nearest terms
WebSearch: configurable display of nearest terms

* Introduces new configuration variable
  CFG_WEBSEARCH_DISPLAY_NEAREST_TERMS that influences whether
  we would like to display the list of nearest terms in case
  the user search does not return any results, or whether we
  display only a general message in this case.

tiborsimko/invenio-records,inveniosoftware/invenio-records,inveniosoftware/invenio-search,tiborsimko/invenio-search,inveniosoftware/invenio-records,inveniosoftware/invenio-search,tiborsimko/invenio-records,tiborsimko/invenio-search