Abstractions for data (particles, branches)

Classes
class	smash::Actions
class	smash::DecayModes
class	smash::EnergyMomentumTensor
class	smash::FourVector
class	smash::IsoParticleType
class	smash::ParticleData
class	smash::Particles
class	smash::ParticleType
class	smash::ParticleTypePtr
class	smash::PdgCode
class	smash::ProcessBranch
class	smash::CollisionBranch
class	smash::DecayBranch
class	smash::QuantumNumbers
class	smash::ThreeVector