Merge branch 'jc/maint-log-grep'

* jc/maint-log-grep:
  log --author/--committer: really match only with name part
  diff --cumulative is a sub-option of --dirstat
  bash completion: Hide more plumbing commands

diff --cc contrib/completion/git-completion.bash
Simple merge

diff --cc diff.c
Simple merge

diff --cc revision.c
Simple merge