Log message:
remove python23 stuff.

Log message:
Simply and speed up buildlink3.mk files and processing.
This changes the buildlink3.mk files to use an include guard for the
recursive include. The use of BUILDLINK_DEPTH, BUILDLINK_DEPENDS,
BUILDLINK_PACKAGES and BUILDLINK_ORDER is handled by a single new
variable BUILDLINK_TREE. Each buildlink3.mk file adds a pair of
enter/exit marker, which can be used to reconstruct the tree and
to determine first level includes. Avoiding := for large variables
(BUILDLINK_ORDER) speeds up parse time as += has linear complexity.
The include guard reduces system time by avoiding reading files over and
over again. For complex packages this reduces both %user and %sys time to
half of the former time.

Log message:
Include pyversion.mk include the protected part of the buildlink3.mk
files, not over and over again.

Log message:
Remove PYBINMODULE. All it did was mark some packages as not available
on some platforms that lacked shared library support in the past. The
list hasn't been maintained at all and the gain is very limited, so just
get rid of it.

Log message:
Add DESTDIR support.

Log message:
Change the format of BUILDLINK_ORDER to contain depth information as well,
and add a new helper target and script, "show-buildlink3", that outputs
a listing of the buildlink3.mk files included as well as the depth at
which they are included.

For example, "make show-buildlink3" in fonts/Xft2 displays:

	zlib
	fontconfig
	    iconv
	    zlib
	    freetype2
	    expat
	freetype2
	Xrender
	    renderproto

Log message:
Track information in a new variable BUILDLINK_ORDER that informs us
of the order in which buildlink3.mk files are (recursively) included
by a package Makefile.

Log message:
Fixed pkglint warnings.

Log message:
Aligned the last line of the buildlink3.mk files with the first line, so
that they look nicer.

Log message:
Over 1200 files touched but no revisions bumped :)

RECOMMENDED is removed. It becomes ABI_DEPENDS.

BUILDLINK_RECOMMENDED.foo becomes BUILDLINK_ABI_DEPENDS.foo.

BUILDLINK_DEPENDS.foo becomes BUILDLINK_API_DEPENDS.foo.

BUILDLINK_DEPENDS does not change.

IGNORE_RECOMMENDED (which defaulted to "no") becomes USE_ABI_DEPENDS
which defaults to "yes".

Added to obsolete.mk checking for IGNORE_RECOMMENDED.

I did not manually go through and fix any aesthetic tab/spacing issues.

I have tested the above patch on DragonFly building and packaging
subversion and pkglint and their many dependencies.

I have also tested USE_ABI_DEPENDS=no on my NetBSD workstation (where I
have used IGNORE_RECOMMENDED for a long time). I have been an active user
of IGNORE_RECOMMENDED since it was available.

As suggested, I removed the documentation sentences suggesting bumping for
"security" issues.

As discussed on tech-pkg.

I will commit to revbump, pkglint, pkg_install, createbuildlink separately.

Note that if you use wip, it will fail!  I will commit to pkgsrc-wip
later (within day).