- fixing remaining issues with bug 109, in particular NPE thrown for getRequestContent and

  getResponseContent after serialization. The idea is, as expalined in comment 3, to make a 
  copy of the contents of various httpRequest and httpResponse fields (without serializing 
  httpRequest and httpResponse). Also note many converters in the c.q.l.acces.Pattern package 
  *cannot* deal with null values returned by various get methods in AccessEvent. Thus, it is not
  enough to avoid NPE as accomplished by attachment 21 (dated 2008-01-28 21:39:11) but also to
  return valid values.

Comment 3: http://bugzilla.qos.ch/show_bug.cgi?id=109#c3