Merge branch 'jn/git-cmd-h-bypass-setup'

Merge branch 'jn/git-cmd-h-bypass-setup'

* jn/git-cmd-h-bypass-setup:
  update-index -h: show usage even with corrupt index
  merge -h: show usage even with corrupt index
  ls-files -h: show usage even with corrupt index
  gc -h: show usage even with broken configuration
  commit/status -h: show usage even with broken configuration
  checkout-index -h: show usage even in an invalid repository
  branch -h: show usage even in an invalid repository

Conflicts:
	builtin/merge.c