moved user cache to session user
Update LookupUser:
- root.identityField added
- Load user by name, email, id and identity
added import
renamed var name to ident
Removed caching from user and root
test update
added sessionuser cache module
sessionuser test updates
switched to new SessionUserCache:
- caches simple readonly users
- stores sessions users as request.authenticated_user
- views.user returns the session user
enabled non-class functions as event callbacks:
  def event_fnc(context, **kw):
      ...