Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

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

MFC r259113, r259115, r259144, r259148:

r259113 (dteske):
Fix failed attempt to send pkg(8) stderr to /dev/null

r259115 (dteske):
Prevent truncating /tmp/bsdinstall_log each time we
exec a module.

r259144 (dteske):
Fix a regression after successfully installing to encrypted
ZFS root, the passphrase is not accepted and a message about
"incorrect key" is displayed.

r259148 (dteske):
Fix a regression resulting in mountroot prompt after attempting
to install to encrypted ZFS root (caused by a typo in a
variable name -- ZFSBOOT_BOOT_FSNAME -> ZFSBOOT_BOOTFS_NAME).

Sponsored by: The FreeBSD Foundation

MFC Revisions:
256549: man-page updates
256551: .Dd bump in manpage
256553: bootenv -> ROOT fix
257842: monster list of fixes
257843: minor touchup
257844: copy install log
257845: fixup to last
257872: mdoc fixup
257939: debug check
258021: MBR bootcode fixup

Reviewed by: many
Discussed on: -current
Approved by: re (hrs)

MFC revisions 256321-256323,256331,256333,256335,256343:
Bring in a new zfsboot auto script for performing automatic setup of a boot
pool (optionally encrypted) with many other options, validations, features.
Originally submitted by Allan Jude; modified in collaboration.

MFC revisions 256325,256330,256345:
Rewrite the keymap selection menu to display keymaps and provide a test
mechanism. Test mechanism originally submitted by Warren Block; modified.

MFC r256347:
Prominently display "Wireless" for each wireless network interface. Part
of PR bin/161547; submitted by Warren Block; slightly modified.

MFC r256348:
Remove the dumpdev configuration dialog, merge it into the regular
services configuration and enable it by default. Originally submitted by
Allan Jude; slightly modified.

PR: bin/161547
Submitted by: Allan Jude, Warren Block <wblock@wonkity.com>
In collaboration with: Allan Jude <freebsd@allanjude.com>
Approved by: re (glebius)

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

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

Optimize syntax to use builtins and reduce unnecessary forking where possible.

Reviewed by: nwhitehorn
Approved by: adrian (co-mentor)

Fix "unexpected operator" error when passed multi-word first-argument
containing whitespace. Also make other changes to support multi-word
arguments.

PR: bin/170759
Submitted by: dteske
Reviewed by: emaste (mentor)
Approved by: emaste (mentor)
MFC after: 3 days

Improve logging by always sending stderr to the installation log file.
Reduce warnings by making sure the temporary etc directory exists.

Add support for optional distributions, installation of the ports tree and
src. Fitting all of this on a single CD along with a full system requires
changing the default compression algorithm from gzip to xz.

Import bsdinstall. This is meant to be (eventually in conjunction with
pc-sysinstall) a replacement for sysinstall in the 9.0 release and beyond.
Currently supported platforms are sparc64, pc98, i386, amd64, powerpc, and
powerpc64. Integration into the build system will occur in the coming
weeks.

Merging with pc-sysinstall will use this code as a frontend, while
temporarily retaining the interactive partition editor here. This work
will be done in parallel with improvements on this code and release
integration.

Thanks to all who have provided testing and comments!