object to instantiate a G4VSensitiveDetector 
    class
    ->  allows to use pre-existing SD classes 
    -> changed macro DECLARE_SENSITIVEDETECTOR to
       create a factory, thus replace:
       //    typedef Geant4GenericSD<TrackerCombine>  Geant4TrackerCombine;
       typedef SimpleG4SDFactory< Geant4GenericSD<TrackerCombine> >  Geant4TrackerCombine;

   in copyNrs

   bool   runDaughterVisibilityWorkaround
   ( change value in code)

    using workaround: setShowDaughters(true) on all volumes
    -> otherwise this attribute is different than specified in
       the compact xml file....

  - add some debug output to Geant4Converter.cpp
    -> visualization works in principle 
       but screen stays black
        -> issue w/ visualization attributes ??

Remove materials from LCDD. Look them directly up in the TGeoManager instance and avoid double caching.

   cellIDs to SimTrackerHits in ILDExSimu
   - use ILDCellIDEncoder (needed for MarlinTrk)
   - uses the G4PhysicalVolume CopyNo
   - so far only SIT and VXD
     TPC hits still missing cellIds (and row-volumes)

  - added Property $Id$ to all *.h *.cpp and *.xml files
    to allow versioning with SVN