Convert packed indices to32 bit - 2016 patches
Backports to the 2016-patches branch the tracking packing improvements from https://gitlab.cern.ch/LHCb-SVN-mirrors/LHCb/merge_requests/77
Backports to the 2016-patches branch the tracking packing improvements from https://gitlab.cern.ch/LHCb-SVN-mirrors/LHCb/merge_requests/77