Fix warning seen on jenkins @ juropagpfs.fz-juelich.de:
../analysis/CubicSpline2D.hh(28): error #1125: function "TObject::Clear(Option_t={const char} *)" is hidden by "Analysis::CubicSpline2D::Clear" -- virtual function override intended?
void Clear();
Fix unit_tests in dev.
Fix clang build on Mac w/o ac_producer:
./EventFactory.hh:84:29: error: private field 'fCfgHandler' is not used [-Werror,-Wunused-private-field]
  Utilities::ConfigHandler* fCfgHandler;
Fix clang build when ac_producer is enabled.