11.0-RELEASE schedule update

As those of you tracking our PR system are probably aware, re_at_ is aware
of an issue related to ZFS and VFS that we feel is urgent enough to have
fixed for 11.0-RELEASE.

https://lists.freebsd.org/pipermail/freebsd-current/2016-August/062829.html

As such, instead of branching releng/11.0 today and starting 11.0-RC1
builds, BETA4 will be added to the 11.0 release schedule, since the
level of possible intrusiveness would be extremely difficult to fix with
an Errata Notice after 11.0-RELEASE.

The 11.0-RELEASE schedule has been updated on the website to account for
the BETA4 addition:

https://www.freebsd.org/releases/11.0R/schedule.html

Thank you for your patience.

Glen
On behalf of:	re_at_