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
Unify realRun() and createTracedPolygon() methods
Fix data availability checks
Unify m_perform* flags
Unify WayEditor finalization
Cleanups
RUIAN: Remove unused imports
LPIS: reuse near nodes
LPIS: remove needless nodes
Fix bug in WayEditor.getModifiedWays()

It returned all EdWays loaded into WayEditor, not only the modified ones.
Consequently, the tracer was a bit more agressive in MergeIdenticalWays
and ReuseNeedlesNodes.
LPIS: increase connect/simplify distance tolerance