Copy stable/9 to releng/9.3 as part of the 9.3-RELEASE cycle.

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

MFC r245177,r245346,r246283,r251650:

- Set WITHOUT_SVN=yes for textproc/docproj.
- Add CHECKSUM.* support in Makefile.
- Use ln -fs to create a symlink.
- Remove pkgadd for docports.
- Use WITHOUT_JADETEX=yes instead of WITH_JADETEX=no.
- Add {WORLD,KERNEL}_FLAGS to [BTWK]MAKE.
- Use makefs(8) and gpart(8) for sparc64 ISO image.
- Add publisher option to makefs(8).
- Add missing copyright notice.
- ISO 9660 specification allows only "d-characters" and "a-characters"
in the Volume Descriptor (section 7.4). In short, uppercase
alphanumeric + some symbols only. While the makefs utility automatically
converts the characters, $LABEL should be consistent in the scripts.

These fix a specification violation in 9.X iso9660 images, and cdrtools
dependency and endianness issue for sparc64 release media. The label is
now in uppercase letters only in all platforms.

Copy head to stable/9 as part of 9.0-RELEASE release cycle.

Approved by: re (implicit)

Provide a kboot.conf to allow powerpc64 install media to be booted on
Playstation 3 consoles running kboot or petitboot.

Approved by: re (bz)

Add an MBR to our release media to aid booting some IBM systems.

Fix pSeries/PAPR boot CD construction after actual testing. It seems that
IBM SLOF is (a) case-sensitive and (b) accepts only booting files in
certain subdirectories of the CD.

Add (somewhat speculative) bootable CD support for PAPR/pSeries-type
systems. In principle, FreeBSD should run on at least some of these
already, and support for the remainder will hopefully show up eventually,
so add this while I'm thinking about it.

Garbage collect some unused variables and stray debug code.

Submitted by: marius

Change the way powerpc bootable CDs are generated to work around a bug
in hybrid image generation in cdrtools. This produces a small HFS partition
containing loader, mapped in by an oddly-formed APM table using a new
feature in makefs. This does not appear to work yet on early-model G3
systems, which will be fixed later, but produces bootable CDs on
everything else.

Use labels to find release media instead of hard-coded device paths. This
makes booting more reliable (and working at all on USB sticks). While here,
move responsibility for setting up fstab into the various platform mk-*.sh
scripts.

Suggested by: many

Fix the overflowing livefs ISO by removing man pages from the HFS part of
the hybrid disk. This is a stopgap until a better solution can be found,
but lets the powerpc release build complete for the time being.

MFC after: 1 week

Replace an obsolete flag -L in an mkisofs(1) command line with
-allow-leading-dots to fix "make release" for FreeBSD/powerpc.

Reviewed by: marcel

Add files needed for PPC release ISOs. These are built with the
HFS/ISO9660 extensions to be bootable on Power Macs.

boot.tbxi - the CHRP script executed by Open Firmware when auto-booting
CDs
hfs.map - map Unix files to HFS creator/type fields

Reviewed by: ru
Submitted by: ssouhlal