removed unneeded include
Not closing Geant4-Geometry in the destructor of the Geant4ePropagator.
Other (cloned) Geant4ePropagators might still use it.
removed legacy matrix transformation code
removed legacy variables and improved comments
Handling particle name as an std::string now
removed unused class forward-declaration
removed debug output
moved debug output functions to the very end of the source files
added comments and clarifed code
added the case for a neutral particle propagation