Do not assume boundary for ARINC 767 data

ARINC 767 data does not contain frames or superframes, therefore the
assumption of 4 or 64 seconds does not apply in this case.
Resolved conflict in split_hdf_to_segments.py for branch cherry pick.
Updated CHANGES for 0.13.4
Bump version: 0.13.3 → 0.13.4