Merge branch 'jc/fsck-reflog'

Merge branch 'jc/fsck-reflog'

* jc/fsck-reflog:
  Add git-reflog to .gitignore
  reflog expire: do not punt on tags that point at non commits.
  reflog expire: prune commits that are not incomplete
  Don't crash during repack of a reflog with pruned commits.
  git reflog expire
  Move in_merge_bases() to commit.c
  reflog: fix warning message.
  Teach git-repack to preserve objects referred to by reflog entries.
  Protect commits recorded in reflog from pruning.
  add for_each_reflog_ent() iterator