gnome.mk: rename gdkpixbuf2 to gdkpixbuf to prepare for port move

The GTK 1-based gdk-pixbuf has not existed for some time.

No functional or package changes.

accessibility/at-spi2-core: update to 2.46.0

What's new in at-spi2-core 2.46.0:
* Fix GetInterfaces documentation on org.a11y.atspi.Accessible
  interface.

What's new in at-spi2-core 2.45.91:
* Send device event controller events using the same signature as other
  events.
* Document the Accessible, Action, and Cache dbus interfaces.
* Fix license of atspi-gmain.c (#87).

What's new in at-spi2-core 2.45.90:
* xml: Add some documentation.
* xml: Fix event arguments.

Remove WWW entries moved into port Makefiles

Commit b7f05445c00f has added WWW entries to port Makefiles based on
WWW: lines in pkg-descr files.

This commit removes the WWW: lines of moved-over URLs from these
pkg-descr files.

Approved by:		portmgr (tcberner)

Add WWW entries to port Makefiles

It has been common practice to have one or more URLs at the end of the
ports' pkg-descr files, one per line and prefixed with "WWW:". These
URLs should point at a project website or other relevant resources.

Access to these URLs required processing of the pkg-descr files, and
they have often become stale over time. If more than one such URL was
present in a pkg-descr file, only the first one was tarnsfered into
the port INDEX, but for many ports only the last line did contain the
port specific URL to further information.

There have been several proposals to make a project URL available as
a macro in the ports' Makefiles, over time.

graphics/mesa-libs: Bump reverse deps for libglvnd

Per discussion with bapt on helping pkg handle the changing of these
deps and avoiding impossible upgrade senarios.

PR:		246767
Reviewed by:	manu, bapt
Approved by:	x11
Differential Revision:	https://reviews.freebsd.org/D30824

One more small cleanup, forgotten yesterday.
Reported by:	lwhsu

Remove # $FreeBSD$ from Makefiles.

science/openbabel: Upgrade 2.4.1 -> 3.1.1

PR:		252309
Submitted by:	thierry

science/luscus: Fix build on 13

Add -fcommon

Reported by:	fallout
MFH:		2020Q3

Add USES=xorg USES=gl, ports categories s

Add USES=xorg and USES=gl to ports in categories starting with 's'
While here, try to sprinkle other USES (mostly gnome and sdl) as needed.

Bump PORTREVISION for ports depending on the canonical version of GCC
as defined in Mk/bsd.default-versions.mk which has moved from GCC 8.3
to GCC 9.1 under most circumstances now after revision 507371.

This includes ports
 - with USE_GCC=yes or USE_GCC=any,
 - with USES=fortran,
 - using Mk/bsd.octave.mk which in turn features USES=fortran, and
 - with USES=compiler specifying openmp, nestedfct, c11, c++0x, c++11-lang,
   c++11-lib, c++14-lang, c++17-lang, or gcc-c++11-lib
plus, everything INDEX-11 shows with a dependency on lang/gcc9 now.

PR:		238330

science/luscus: fix build with GCC-based architectures

Add USES=compiler:c++11-lang to fix linking:
/usr/local/lib/libgraphite2.so.3: undefined reference to
`__cxa_throw_bad_array_new_length@CXXABI_1.3.8'

Approved by:	mentors (implicit approval)

Change cmake default behaviour to outsource.

Ports that build out of source now simply can use "USES=cmake"
instead of "USES=cmake:outsource". Ports that fail to build
out of source now need to specify "USES=cmake:insource".

I tried to only set insource where explictely needed.

PR:		232038
Exp-run by:	antoine

Sscience/luscus: Update 0.8.5 -> 0.8.6

Reported by:	portscout

New port: science/luscus: Molecular editor and viewer