sixtracklib/common: Bugfixing and adaptions to the Particles helpr functions
sixtracklib/common: Bugfixing and adaptions to the Particles helpr functions

- Change the output format of the print routine to be more usefull for
  displaying small differences

- set p0c to the (unphysical, but non-pathological) value of 1 instead of 0
  for random init of particles.

TODO: provide a function to initialize the particles with "real-world" data from
      testdata/test_tracking_lhc.txt

SixTrack/SixTrackLib,SixTrack/SixTrackLib,SixTrack/SixTrackLib,SixTrack/SixTrackLib