textproc/libxml2: bump all LIB_DEPENDS consumers

This is a separate commit to facilitate easier cherry-picking for
quarterly.

PR: 262853, 262940, 262877, 263126
Approved by: fluffy (mentor)

textproc/libxml2: bump all dependencies

This should make sure that all dependent ports will pick
up the new version commited with a13ec21cd733f67a9fc0dc00ab45268bdc236246

misc/qtchooser: remove

QtChooser allows you to select your version of Qt among those installed.
However, this tool is no longer supported upstream and will not be
available for Qt6.
By default, our Qt installations are done in
${LOCALBASE}/lib/qt${QT_VERSION} as recommended.

We have added symbolic linking for the main binaries to
${LOCALBASE}/bin with the suffix -qt5.

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.

audio/abgate-lv2: Update 1.1.9 -> 1.2.0

Reported by:	portscout

audio/abgate-lv2: Unbreak

It got broken when audio/lv2 was upgraded to 1.18.0.

MFH:		2020Q4

Mark BROKEN

Reported by:	pkg-fallout

Add USES=xorg USES=gl, ports categories a

Add USES=xorg, USES=gl and in a few cases USES=gnome to ports in categories
starting with 'a'.

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

Add compiler:c++11-lang to USES to unbreak build on powerpc64:

  cc1plus: unrecognized command line option -std=c++11

Approved by:	portmgr (tier-2 blanket)

Fix Qt5 symbol version scripts to put the catch-all clause first.  When
a symbol matches multiple clauses the last one takes precedence.  If the
catch-all is last it captures everything.  In the case of Qt5 libraries
this caused all symbols to have a Qt_5 label while some should have
Qt_5_PRIVATE_API.  This only affects lld because GNU ld always gives the
catch-all lowest priority.

Older versions of Qt5Webengine exported some memory allocation symbols from
the bundled Chromium.  Version 5.9 stopped exporting these [1] but the
symbols were kept as weak wrappers for the standard allocation functions to
maintain binary compatibility. [2][3]  The problem is that the call to the
standard function in these weak wrappers is only resolved to the standard
function if there's a call to this standard function in other parts of
Qt5Webengine, because only then is there a non-weak symbol that takes
precedence over the weak one.  If there's no such non-weak symbol the call

Replace bsd.qt.mk by Uses/qt.mk and Uses/qt-dist.mk

From now on, ports that depend on Qt4 will have to set
	USES=		qt:4
	USE_QT=		foo bar
ports depending on Qt5 will use
	USES=		qt:5
	USE_QT=		foo bar

PR:		229225
Exp-run by:	antoine
Reviewed by:	mat
Approved by:	portmgr (antoine)
Differential Revision:	-https://reviews.freebsd.org/D15540

These ports are not quite ready for the tier-2 archs yet.

These are probably trivial fixes, if someone has the time and interest
to pursue them.  I'm definitely short of time ATM.

Approved by:	portmgr (tier-2 blanket)

audio/abgate-lv2: Switch to Qt5

The project has officially switched to Qt5 in the last revision, but old
qmake was still accidentally used. Now this is fixed.

New port: audio/abgate-lv2: Noise gate LV2 plugin

PR:		221683
Approved by:	tcberner (mentor)
Differential Revision:	https://reviews.freebsd.org/D12986