WebApiKey: initial release
WebApiKey: initial release

* Initial release of the user-signed Web API key facility.
  (closes #806)

* Adds an admin interface to view/edit user's Web API keys.

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