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;

Not yet in operation and some of the headerfiles need to be
cleaned up. Need to remove physics.h.

At the moment the matched distribution generator is not enabled! 

- moving the following classes over from OPAL to CLASSIC
  o OpalField       -> ClassicField
  o OpalRing        -> Ring
  o OpalRingSection -> RingSection
  o LossDataSink
- clean up
- splitting Options into classic and opal options

 - remove configure file
 - extend ParticleAttriIterator and its const variant to random access iterators

- putting own header file first
  o for reason see http://www.cplusplus.com/forum/articles/10627/#msg49679 and
                   http://www.cplusplus.com/forum/articles/10627/#msg49680

- updating .gitignore

xpang: fixed a bug in CSRWakefunction.cpp and added CSRIGFWakefunction.cpp for the integrated green function method