update the header as well. the updateGainK function returns a TMatrixD and not a const ref to it

-        const TMatrixD& updateGainK( const EUTelTrackStateImpl*, const EVENT::TrackerHit* );
+        TMatrixD updateGainK( const EUTelTrackStateImpl*, const EVENT::TrackerHit* );
update the code to use the EUTelGeo interface
update the code to use EUTelGeo interface

-  if (header->getGeoID() != geo::gGeometry()._siPlanesParameters->getSiPlanesID()) {

to

+  if (header->getGeoID() != geo::gGeometry().getSiPlanesLayoutID()) {
bug fix: histogrammer crashing, have to check if exists, otherwise use defaults