Merge branch '48_particle_creator' into 'master'

Framework/Utilities/CorsikaFenvOSX.cc

Framework/Utilities/Singleton.h

Framework/Utilities/testCOMBoost.cc

Framework/Utilities/testCorsikaFenv.cc

Framework/Utilities/try_feenableexcept.cc

Main/Environment.h

Main/Stack.h

Main/shower.cc

Processes/HadronicElasticModel/HadronicElasticModel.cc

Processes/HadronicElasticModel/HadronicElasticModel.h

Processes/NullModel/NullModel.cc

Processes/NullModel/NullModel.h

Processes/NullModel/testNullModel.cc

Processes/Sibyll/Decay.h

Processes/Sibyll/Interaction.h

Processes/Sibyll/ParticleConversion.cc

Processes/Sibyll/ParticleConversion.h

Processes/Sibyll/SibStack.h

Processes/Sibyll/sibyll2.3c.cc

Processes/Sibyll/sibyll2.3c.h