Added a new GeometryHandlerTraits class that will be used in the generic ParticleSimulationManager class. All geometry handlers will have to specialize the GeometryHandlerTraits class in order to be used by the ParticleSimulationManager class. The ParticleState class will be used as the glue between all of the different managers in the ParticleSimulationManager class. I have started unit testing this class. Once the unit tests are complete, unit tests for the GeometryHandlerTraits class specializations will be written. The most important will be the specialization for DagMC.