bug#35418: [PATCH] Don't poll auto-revert files that use notification

[Eli Zaretskii]

> From: Michael Albinus <michael.albinus@gmx.de>
> Cc: Eli Zaretskii <eliz@gnu.org>,  35418@debbugs.gnu.org
> Date: Sat, 04 May 2019 18:53:07 +0200
> 
> Maybe we could also add the other major reason why polling is necessary:
> file notification is not supported for all types of remote file systems
> (Tramp).

Yes, I think all the reasons should be mentioned, so that users who
disable polling know what they are/will be losing, and could make
educated decisions.