There is a change in behaviour with this commit. When there was
no initial commit, the shell version of stash would still display
a message. This commit makes `push` to not display any message if
`--quiet` or `-q` is specified. Add tests for `--quiet`.
Signed-off-by: Paul-Sebastian Ungureanu <ungureanupaulsebastian@gmail.com> Signed-off-by: Thomas Gummerer <t.gummerer@gmail.com> Signed-off-by: Junio C Hamano <gitster@pobox.com>