Fixes#1076
It can be enabled with a config like
~/.config/labwc/rc.xml:
<keyboard layoutScope="window">
~/.config/labwc/environment:
XKB_DEFAULT_LAYOUT=de,us
XKB_DEFAULT_OPTIONS=grp:alt_shift_toggle,grp_led:scroll
With a configuration like this each window should now remember
the active keyboard layout when switching between windows.
By default, the keyboard layout keeps being a global state.