Merge branch 'jc/rev-parse-argh-dashed-multi-words'

Merge branch 'jc/rev-parse-argh-dashed-multi-words'

Make sure that the help text given to describe the "<param>" part
of the "git cmd --option=<param>" does not contain SP or _,
e.g. "--gpg-sign=<key-id>" option for "git commit" is not spelled
as "--gpg-sign=<key id>".

* jc/rev-parse-argh-dashed-multi-words:
  parse-options: make sure argh string does not have SP or _
  update-index: teach --cacheinfo a new syntax "mode,sha1,path"
  parse-options: multi-word argh should use dash to separate words