tcktruncate: ported from old 0.2 truncate_tracks. Added option to skip N tracks before truncating
tcktruncate: ported from old 0.2 truncate_tracks. Added option to skip N tracks before truncating

MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3,MRtrix3/mrtrix3