fdupes 1.6.0

Changes from 1.51 to 1.6.0:

• Add --nohidden option.
• Add --permissions option.
• Add --order option.
• Add --reverse option.
• Add --immediate option.
• Speed up file comparison.
• Fix bug where fdupes fails to consistently ignore hardlinks, depending on
  file processing order, when F_CONSIDERHARDLINKS flag is not set.
• Fix bug in is_hardlink(): Proper traversal of duplicates is done via
  dupe->duplicates, not via dupe->next.
• Revise md5.c to compile under OSX.
• Remove EXTERNAL_MD5 configuration option.
• Various other changes (see git log).