Merge branch 'ab/doc-cat-file-e-still-shows-errors'

Doc update. * ab/doc-cat-file-e-still-shows-errors: cat-file doc: document that -e will return some output

Junio C Hamano committed Jan 23, 2018 at 13:16 UTC 93a622f4a73f9dd5277d32c5ecce534bdbc40a1b

No changes.