"git blame" learned to "ignore" commits in the history, whose
effects (as well as their presence) get ignored.

* br/blame-ignore:
  t8014: remove unnecessary braces
  blame: drop some unused function parameters
  blame: add a test to cover blame_coalesce()
  blame: use the fingerprint heuristic to match ignored lines
  blame: add a fingerprint heuristic to match ignored lines
  blame: optionally track line fingerprints during fill_blame_origin()
  blame: add config options for the output of ignored or unblamable lines
  blame: add the ability to ignore commits and their changes
  blame: use a helper function in blame_chunk()
  Move oidset_parse_file() to oidset.c
  fsck: rename and touch up init_skiplist()