wayland client with native bindings

[Antoine Martin]

Following up #2243, we will need some form of native bindings to:

• query the keyboard layout
• access the clipboard

etc..

[Antoine Martin]

According to ​libxkbcommon quick guide: If we are a Wayland client, the compositor gives us a string complete with a keymap.
Not sure where, no attributes in the GTK.EventKey, or in its GdkWaylandDevice attribute..

More keyboard related tickets: #1049, #856

[mviereck]

Keyboard:
On systems with systemd the output of localectl status might be a good guess.
The Wayland compositor might still be configured different, but I assume most systems will have the same keyboard configuration on tty as on the desktop.
On my german system I get the same valid output on tty, in X and in Wayland:

$ localectl status
   System Locale: LANG=de_DE.UTF-8
       VC Keymap: n/a
      X11 Layout: de
       X11 Model: pc105

[Antoine Martin]

On systems with systemd the output of localectl status might be a good guess.

Thanks, added this as fallback in r23321.