Log Message:
Changes 5.2.1:
* Fixed a compression-ratio regression in fast mode of LZMA1 and
  LZMA2. The bug is present in 5.1.4beta and 5.2.0 releases.
* Fixed a portability problem in xz that affected at least OpenBSD.
* Fixed xzdiff to be compatible with FreeBSD's mktemp which differs
  from most other mktemp implementations.
* Changed CPU core count detection to use cpuset_getaffinity() on
  FreeBSD.