Update .gitignore
Add a new helper for tracking user idle activity

When running as a wayland compositor, we can't use the xserver's
IDLETIME, because that's updated only in response to X events.
But we have all the events ourselves, so we can just run the timer
in process.

https://bugzilla.gnome.org/show_bug.cgi?id=706005
MetaIdleMonitor: add a DBus interface for the idle monitor

To allow other clients (gnome-session, gnome-settings-daemon)
to monitor user activity, introduce a DBus interface for the
idle monitor inside mutter.

https://bugzilla.gnome.org/show_bug.cgi?id=706005
MetaIdleMonitor: add wayland support

Keep a timer source that we reset when we capture an event in
MetaWayland, and fire watches accordingly.

https://bugzilla.gnome.org/show_bug.cgi?id=706005
MonitorXrandr: fix reading the current DPMS level

Add missing break statements, to avoid falling always through
to the invalid case.

https://bugzilla.gnome.org/show_bug.cgi?id=706582
MonitorXrandr: Fix segv when accessing possible_clones

This code requires a double pass and the segv happens later
when trying to iterate over the array.

https://bugzilla.gnome.org/show_bug.cgi?id=706598
MonitorXrandr: skip CRTC reconfigurations that have no effect

If we're attempting to reconfigure the CRTCs to the same parameter,
skip the X call, as in some drivers a modeset can take time and
cause flicker.

https://bugzilla.gnome.org/show_bug.cgi?id=706672
Update .gitignore
wayland-private: Ignore deprecations around legacy_buffer

yes, it's deprecated, that's why it's marked legacy. now shush.
wayland: Fix build when building without Wayland
window-group: Fix compiler warning
window: Fix a compiler warning
MetaShapedTexture: don't include private headers in public ones

Private headers are not installed, so they can't be referenced
from public ones.

https://bugzilla.gnome.org/show_bug.cgi?id=705497
build: make wayland support unconditional

In the wayland branch of mutter, we want to build a wayland version
of the mutter libraries, and that's much easier if we just build
wayland support unconditionally.
The define is kept to avoid a huge diff, but should be removed
in a later patch.
Also, wayland support can still be disable at runtime, by
launching mutter without the --nested switch.

https://bugzilla.gnome.org/show_bug.cgi?id=705497
Remove HAVE_WAYLAND ifdefs

Wayland support is always enabled now.

https://bugzilla.gnome.org/show_bug.cgi?id=705497
Remove files no one cares about anymore

mutter-plugins.pc has been replaced by libmutter.pc, and the
wm properties in the control center are long gone.

https://bugzilla.gnome.org/show_bug.cgi?id=705497
wayland: make parallel installable with regular mutter

Modify all visible instances of mutter with mutter-wayland
(libraries, folders, pkgconfig, etc.), so that the wayland
branch can be installed alongside the usual X11 mutter.

https://bugzilla.gnome.org/show_bug.cgi?id=705497
Bump version to 3.9.90

gnome-shell requires mutter and mutter-wayland at the same version
to build. Also update NEWS, cherry-picked from master.
window: ignore skip-taskbar hint on parentless dialogs

Dialogs that don't have a parent should not be skip-taskbar,
otherwise they get lost and there is no way to recover them
(because they're not autoraised when activating the parent),
but toolkits and applications set the hint anyway.

https://bugzilla.gnome.org/show_bug.cgi?id=673399
background: don't save pixbuf in user data

https://bugzilla.gnome.org/show_bug.cgi?id=706777