Put record geometries to a common base class TracerRecord
RUIAN: don't ignore geometry parser exceptions
RUIAN: RuianRecord cleanups
Introduce common base class for all TracerTasks
Move common functions to AbstractTracerTask
TracerTask.realRun() doesn't throw SAXException
Unify cancellation and data availability checks
Don't access m_record variables directly
Move m_postTraceNotifications to AbstractTracerTask