Merge branch 'release_29'

* release_29:
  BP5Deserialize: modify changes to keep abi compt
  Rename test. fix windows compile errors.
  Fix ChunkV maintaining CurOffset when downsizing current chunk in Allocate() and creating the next chunk.
  remove data.py since BP5 data file has no format
  format
  bp5dbg parse records and check sizes during it for mmd.0 and md.0. No decoding FFS records.
  Organize the processes into groups so that the two steps of metadata aggregation has more or less the same number or participants. This replaces in-node aggregation in first step. The new strategy balances the size of metadata gathered in the two steps.