wayland: constraint the pointer onto visible monitors when running on evdev

Use the new Clutter hook to make sure the pointer never enters
the dead area caused by the different monitor sizes.

You don't realize how much X is doing for you until you lose it...

https://bugzilla.gnome.org/show_bug.cgi?id=706655
[NOT FOR REVIEW] Add the ability to attach a debugger at init
Set DISPLAY and WAYLAND_DISPLAY for dbus activated services and for autostarted apps

Call the appropriate method on gnome-session so that autostarted
and bus activated apps see the X server and wayland socket.

https://bugzilla.gnome.org/show_bug.cgi?id=706421
Stop messing with process groups

We can be launched by gnome-session now, which implies gdb must be
attached from outside, and the Ctrl-C problem is gone.

https://bugzilla.gnome.org/show_bug.cgi?id=706421
wayland: don't require Clutter backend variables to be set from outside

When running under mutter-launch, we can assume we're running on
bare metal, and set the clutter backend appropriately.

https://bugzilla.gnome.org/show_bug.cgi?id=706421
wayland: die when gnome-session asks us to

At logout, we want to die when gnome-session tells us. Previously,
we were relying on the X server going down (killed by GDM at the
end of the session), but we can't use that in wayland.

https://bugzilla.gnome.org/show_bug.cgi?id=706421
wayland: implement resizing and maximization for wayland clients

To properly resize clients, we need to send them configure events
with the size we computed from the constraint system.
Also, once the sizing is properly wired up, we need to make
sure that the size at the initial map is correct, and not
always 0, 0 (because the buffer is not yet converted into
a CoglTexture by MetaShapedTexture), otherwise we end up sending
out configure events at 1 x 1. To do so, we cache the surface
type in the initial state until the first commit.

Note that this does not handle interactive resizing yet, it
merely makes the API calls work for wayland clients.

While we're there, let's implement transient hints too.
(I may have to separate this out...)

https://bugzilla.gnome.org/show_bug.cgi?id=707401
wayland: implement global and window keybindings

Synthetize XInput events from ClutterEvents in MetaWaylandKeyboard,
and pass them to the keybindings infrastructure for early handling,
so that we can activate them even if the currently focused window
is not an X11 one (or if there is no focused window, or we're
modal)

https://bugzilla.gnome.org/show_bug.cgi?id=706963
wayland: reimplement keyboard state handling properly

We can't rely on clutter's xkb_state, because that's updated
when events are pulled from the kernel, not when we see them.
Instead, use the new clutter API to get the full modifier state
from the event (which, as a side effect, also works when clutter
is using the X11 backend for running nested).

https://bugzilla.gnome.org/show_bug.cgi?id=706963
wayland: sync the keymap from X to wayland

When X clients change the keyboard map, the also update a property
on the root window. We can notice that and rebuild our data structures
with the new values, as well as inform the wayland clients.

This is a terrible hack, and it's not how we want to implement things
in 3.12, but it's enough to have the same keyboard layout in the
shell, in X clients and in wayland clients in 3.10, until we decide
on the fate of the keyboard g-s-d plugin.

https://bugzilla.gnome.org/show_bug.cgi?id=707446