Copy stable/11@r303970 to releng/11.0 as part of the 11.0-RELEASE
cycle.

Prune svn:mergeinfo from the new branch, and rename it to RC1.

Update __FreeBSD_version.

Use the quarterly branch for the default FreeBSD.conf pkg(8) repo and
the dvd1.iso packages population.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head@r302406 to stable/11 as part of the 11.0-RELEASE cycle.
Prune svn:mergeinfo from the new branch, as nothing has been merged
here.

Additional commits post-branch will follow.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Fix EFI platform build failures

With warnings now enabled some plaforms where failing due to warnings.
* Fix st_size printed as a size_t when its actually an off_t.
* Fix pointer conversion in load_elf for some 32bit platforms due to 64bit
off in ef.

MFC after: 2 days
X-MFC-With:
Sponsored by: Multiplay

Fix EFI multi device boot support

Fix EFI boot support when presented with multiple valid boot partitions
across multiple devices.

It now prefers to boot from partitions that are present on the underlying
device that the boot1 image was loaded from. This means that it will boot
from the partitions on device the user chose from EFI boot menu in
preference to those on other devices.

Also fixed is the recovery from a failed attempt to boot, from a seemingly
valid partition, by continuing to trying all other available partitions
no matter what the error.

boot1 now use * to signify a partition what was accepted from the preferred
device and + otherwise.

Finally some error messages where improved and DPRINTF's with slowed boot
to aid debugging.

ZFS will still be preferred over UFS when both are available on the boot
device.

Reviewed by: imp
MFC after: 1 week
Sponsored by: Multiplay
Differential Revision: https://reviews.freebsd.org/D5108

Fix EFI_DEBUG option

Fix broken DPRINTF and wire up EFI_DEBUG so -DEFI_DEBUG to make works.

MFC after: 2 weeks
X-MFC-With: r293268
Sponsored by: Multiplay

Add EFI ZFS boot support

This builds on the modular EFI loader support added r294060 adding a
module to provide ZFS boot support on EFI systems.

It should be noted that EFI uses a fixed size memory block for all
allocations performed by the loader so it may be necessary to tune this
size.

For example when building an image which uses mfs_root e.g. mfsbsd, adding
the following to /etc/make.conf would be needed to prevent EFI from running
out of memory when loading the mfs_root image.
EFI_STAGING_SIZE=128

Submitted by: Eric McCorkle
MFC after: 2 weeks
X-MFC-With: r293268
Sponsored by: Multiplay