bug#36933: Default option for rgrep -r is not supported with zgrep

[Jean Louis]

* Robert Weiner <address@hidden> [2019-08-06 05:42]:
> Unless you are using the FreeBSD variant of zgrep which support all 3 of
> -r, --include and --exclude.  It would be nice if everyone got together and
> supported all the same options.  It is unusual for the GNU project to have
> a grep-related utility that doesn't support all of the options in their own
> grep program.

Reference:
https://lists.gnu.org/archive/html/bug-gzip/2006-12/msg00075.html