Added a ReferenceField widget
Also removed the unused ReadOnlyBool widget (as we now have a
properlyworking ReadOnly widget).
Patch by: Sverre Rabbelier
# Directions for web crawlers.
# See http://www.robotstxt.org/wc/norobots.html.
User-agent: HTTrack
User-agent: puf
User-agent: MSIECrawler
User-agent: Nutch
Disallow: /