bug#28834: 25.1; dired-do-copy: allow to copy into a nonexistent directory

[Eli Zaretskii]

> From: Tino Calancha <tino.calancha@gmail.com>
> Cc: 28834@debbugs.gnu.org,  drew.adams@oracle.com
> Date: Tue, 17 Oct 2017 13:49:34 +0900
> 
> * I have changed the new function name to `dired-maybe-create-dirs'
>   as Drew suggested.
> * I think I have addressed all your comments as well.

Thanks, this LGTM.  One minor comment:

> +(defun dired-maybe-create-dirs (dir)
> +  "Create DIR if doesn't exist according with 
> `dired-create-destination-dirs'."
                                  ^^^^^^^^^^^^^^
"according to"

Please push to master in a few days, if no one raises any issues.