CYKLO-959: A URL rewriting registry, delegating to abstract
participants.
CYKLO-960: base class for resource-based UrlRewriteParticipants
CYKLO-961: UrlRewritePariticpant implementation for NavigationNodes
CYKLO-962: REST resource for discovering, checking and deleting paths.
CYKLO-959: return a copy of a set to ensure safe iteration
CYKLO-959: save resource data to DB