Merge branch 'maint'

* maint:
  add: introduce add.ignoreerrors synonym for add.ignore-errors
  bash: Match lightweight tags in prompt
  git-commit.txt: (synopsis): move -i and -o before "--"

diff --cc Documentation/config.txt
Simple merge

diff --cc builtin/add.c
Simple merge

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