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.

python: bump all USE_PYTHON=distutils consumers after RUN_DEPENDS removal

Any missed ports, feel free to bump.

Any ports that need setuptools at runtime can have the devel/py-setuptools
manually added back to RUN_DEPENDS, but understand that this practice
is deprecated; see CHANGES for details.

devel/py-pygobject: bump consumer PORTREVISIONs after port rename

With hat: gnome
PR: 273722

*/*: Bump consumers of x11-toolkits/gtk30

New version of gtk3 in tree

all: remove explicit versions in USES=python for "3.x+"

The logic in USES=python will automatically convert this to 3.8+ by
itself.

Adjust two ports that only had Python 3.7 mentioned but build fine
on Python 3.8 too.

finance/quickfix: mark BROKEN with PYTHON

libtool: compile:  c++ -DHAVE_CONFIG_H -I. -I../.. -I -I. -I.. -I../.. -I../C++
-DLIBICONV_PLUG -DPYTHON_MAJOR_VERSION=3 -Wno-unused-variable
-Wno-maybe-uninitialized -O2 -pipe -DLIBICONV_PLUG -fstack-protector-strong
-fno-strict-aliasing -DLIBICONV_PLUG -Wall -ansi
-Wno-unused-command-line-argument -Wpointer-arith -Wwrite-strings
-Wno-overloaded-virtual -Wno-deprecated-declarations -Wno-deprecated -std=c++0x
-MT _quickfix_la-QuickfixPython.lo -MD -MP -MF
.deps/_quickfix_la-QuickfixPython.Tpo -c QuickfixPython.cpp  -fPIC -DPIC -o
.libs/_quickfix_la-QuickfixPython.o
warning: unknown warning option '-Wno-maybe-uninitialized'; did you mean
'-Wno-uninitialized'? [-Wunknown-warning-option]
QuickfixPython.cpp:175:11: fatal error: 'Python.h' file not found
          ^~~~~~~~~~
1 warning and 1 error generated.

Reviewed by:	portmgr, vishwin, yuri
Differential Revision:	<https://reviews.freebsd.org/D40568>

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.

framework: convert bsd.gstreamer.mk to Uses/gstreamer.mk

- convert bsd.gstreamer.mk to Uses/gstreamer.mk
- convert ports tree to make use of USES=gstreamer
- remove duplicate dependency lines from the tree

Differential Revision: https://reviews.freebsd.org/D35097

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

Remove # $FreeBSD$ from Makefiles.

Update to 2.2.0

Changelog: https://github.com/pulb/mailnag/releases/tag/v2.2.0

Add a new port mail/py-mailnag

Mailnag is a daemon program that checks POP3 and IMAP servers for new
mail. On mail arrival it performs various actions provided by
plugins. Mailnag comes with a set of desktop-independent default
plugins for visual/sound notifications, script execution etc. and can
be extended with additional plugins easily.

WWW: https://github.com/pulb/mailnag