GitLab

    - fixing number of particles when the numbers don't add up to the total due to rounding errors;
    - clean up: rename files to comply with coding guide lines;
    - improve message when field of bend overlapps;
    - warning is emitted if too few fourier coefficients are used to filter the field map;

std::regex does not seem to work properly on merlin; switching to boost::regex; don't write to H5 file if there are no particles in the bunch

fixing restart: can now (again) restart from any step in any H5Part file that was written for/with OPAL; SDDS file and load balance file are rewound to an s-position less or equal as in the H5file

- doBGphysics() renamed to emitSecondaryNone(),
  emitSecondaryFurmanPivi() resp. emitSecondaryVaughan()
- cleanup