…. This can call fdatasync() to ensure writing to disk

…. This can call fdatasync() to ensure writing to disk

…in-posix

* 'filedrain-posix' of github:pnorbert/ADIOS2:
  fsync data less frequently, but read/write in small pieces
  Add a POSIX version of file drainer to be used on non-Windows machine. This can call fdatasync() to ensure writing to disk
  Added python full interface description.
  Added description for adios2_attribute_data fortran functions.
  Fixed description for adios2_set_steps_selection fortran function.
  Modified python test to read strings
  fixed a bug in dataman sz compression subroutine
  RDMA error checking and finalize reordering
  clean-up
  Added tests
  Kill warnings
  Disable LocalMulti for other engines
  Work around a bug in BP marshalling in SST
  Support for multiple local blocks per rank in FFS marshalling
  Fix brew mac build python install problem
  for debugging sz test
  included file
  added test for dataman sz compression