* citserver.c: added another trace message to is_public_client(). Uncensored

* citserver.c: added another trace message to is_public_client().  Uncensored
  has crashed twice in this function, for no apparent reason.
* internet_addressing.c: don't attempt to look up the specified Internet
  address in a Citadel directory, if the supplied address has no hostname
  portion.  (Fixes a crash in the calendar service when alias() attempts to
  look up potentially nonexistent attendees during event validation)