INSTALLS_ICONS: retire the macro and rework the related dependencies

While here, make sure gtk-update-icon-cache is only on run dependency
where added as a dependency
Enforce gtk3 to depend on gtk-update-icon-cache (previously it was
inheriting the dependency)

x11/lightdm-gtk-greeter: and x11/slick-greeter: auto-set greeter-session

Add pkg-install and pkg-deinstall scripts to automatically configure
the greeter-session variable in lightdm.conf if it has not been manually
changed from the default value.

This reduces the steps for a fresh FreeBSD install to get to a graphical
environment to the following simple steps (excluding graphics drivers):
$ pkg install <greeter> <desktop-environment>
$ service lightdm enable
$ service ligthdm start

Approved by:	ericbsd (maintainer x11/slick-greeter)
Approved by:	madpilot (maintainer x11/lightdm-gtk-greeter)

Differential Revision: https://reviews.freebsd.org/D31632

x11/lightdm-gtk-greeter: Fix some dependency issues

- Add explicit dependency on accessibility/at-spi2-core
- Disable indicator-services-command option, which tries to launch
  systemd

PR:		254469

x11/lightdm: assign maintainership to desktop@

Also assign reference gtk greeter x11/lightdm-gtk-greeter.

*/*: Fix ENOTIME: return my ports to the pool

Reset maintainership of my ports to ports@FreeBSD.org so others can
step in to help where I haven't been able to find the time.

Remove # $FreeBSD$ from Makefiles.

- Update lightdm-gtk-greeter to 2.0.8
- Remove dependency on libexo exo-csource which has been deprecated
  upstream and add one on xfce4-dev-tools xdt-csource

Approved by:		woodsb02 (maintainer)
Differential Revision:	https://reviews.freebsd.org/D26224

x11/lightdm-gtk-greeter: Update to 2.0.7

This update fixes a bug which could cause lightdm to crash on start-up:
- Remove mlockall to fix high memory pressure startup

Changes this release:
 
https://git.launchpad.net/lightdm-gtk-greeter/tree/NEWS?id=lightdm-gtk-greeter-2.0.7

Add USES=xorg USES=gl, ports categories x

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

x11/lightdm-gtk-greeter: fix build with GCC-based architectures

Add USE_CSTD=c99 to fix:
lightdm-gtk-greeter.c: In function 'start_authentication':
lightdm-gtk-greeter.c:2023: error: 'for' loop initial declaration used outside
C99 mode

PR:		237626
Approved by:	woodsb02 (maintainer), mat (mentor)
Differential Revision:	https://reviews.freebsd.org/D20094

x11/lightdm-gtk-greeter: Update to 2.0.6

Changes this release:
 
https://git.launchpad.net/lightdm-gtk-greeter/tree/NEWS?id=lightdm-gtk-greeter-2.0.6

Add DOCS options to ports that should have one.

Also various fixes related to said option.

PR:		230864
Submitted by:	mat
exp-runs by:	antoine

x11/lightdm: Update to 1.22.0

- Update PAM file to include system defaults
- Set PATH to default from /etc/login.conf
- Don't pass-through empty PATH from lightdm to X11 (breaks runtime)

x11/lightdm: Fix locale selection

- Allow locale selection on login screen. First, lightdm must be patched
  to correctly detect utf8 locales, which have a UTF-8 suffix on FreeBSD
  instead of utf8 like on Linux systems. Secondly, we have to use locale
  codes in the language menuitem as FreeBSD doesn't have support for
  locale naming (missing _NL_IDENTIFICATION_LANGUAGE implementation).

- Use @sample for lightdm-gtk-greeter config file to prevent it from
  being overwritten when the package is reinstalled / upgraded.

PR:		220614
Submitted by:	pawel
MFH:		2017Q3

Add x11/lightdm and x11/lightdm-gtk-greeter.

Lightdm is a display manager that:
* Is cross-desktop - supports different desktops
* Supports different display technologies
* Is lightweight - low memory usage and fast performance
* Has a comprehensive test suite

WWW: https://www.freedesktop.org/wiki/Software/LightDM/

lightdm-gtk-greeter is the reference GTK+ greeter for LightDM.

WWW: https://launchpad.net/lightdm-gtk-greeter

Approved by:	adamw (mentor, implicit)