Log message:
Fix indentation in buildlink3.mk files.

The actual fix as been done by "pkglint -F */*/buildlink3.mk", and was
reviewed manually.

There are some .include lines that still are indented with zero spaces
although the surrounding .if is indented. This is existing practice.

Log message:
Add SHA512 digests for distfiles for x11 category

Problems found locating distfiles:
        Package modular-xorg-server: missing distfile xorg-server-1.17.4.tar.bz2
        Package py-qt4: missing distfile PyQt-mac-gpl-4.11.1.tar.gz
        Package xservers: missing distfile xservers-3.3.6.5.tar.bz2
        Package xview-clients: missing distfile xview3.2p1-X11R6.tar.gz
        Package xview-lib: missing distfile xview3.2p1-X11R6.tar.gz

Otherwise, existing SHA1 digests verified and found to be the same on
the machine holding the existing distfiles (morden).  All existing
SHA1 digests retained for now as an audit trail.

Log message:
Fixes:

 COMMENT should not be longer than 70 characters.
 COMMENT should not begin with 'A'.
 COMMENT should not begin with 'An'.
 COMMENT should not begin with 'a'.
 COMMENT should not end with a period.
 COMMENT should start with a capital letter.

pkglint warnings. Some files also got minor formatting, spelling, and style
corrections.

Log message:
Drop superfluous PKG_DESTDIR_SUPPORT, "user-destdir" is default these days.

Log message:
Remove @dirrm entries from PLISTs

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:
Switch master site to MASTER_SITE_XORG.

Log message:
libxkbui does not depend on libXt (as per Matthieu Herrb).  Thus,
remove this depedency from Makefile, b3.mk, configure scripts,
and xkbui.pc.in.  Bump Rev.

Log message:
Fix redirect to native X11 to address PR 35558.

Log message:
Reimport libxkbui under correct path.