Add settings for titlebar actions

These match the GSettings that mutter/metacity/gnome-shell have
for this. We change the default for the middle-click action to
none, since lower is just a terrible default.

We're slightly bending the rules here, since we're adding new
settings after .0, but a) it is just barely after .0, and b) settings
are not really application API.

https://bugzilla.gnome.org/show_bug.cgi?id=729782
Implement titlebar action settings for X11

https://bugzilla.gnome.org/show_bug.cgi?id=729782
Implement titlebar action settings for Wayland

https://bugzilla.gnome.org/show_bug.cgi?id=729782
Factor out titlebar click actions

So they can be made configurable.

https://bugzilla.gnome.org/show_bug.cgi?id=729782
Use titlebar action settings for CSD windows

Instead of hardcoding these actions, consult the settings.
Note that not all of the actions supported by gnome-shell are
implemented here, only maximize, minimize, lower, and menu.

https://bugzilla.gnome.org/show_bug.cgi?id=729782
button: Fix ::clicked emission on touchscreens sending pointer events

When GtkGestureMultiPress::released happens, in_button should be unset
after emitting GtkButton::released, whose default implementation uses it.
Moreover, in_button should only be unset there for real touch events, not
guaranteed to trigger crossing events, as opposed to every pointer/touch
events from touchscreens.

https://bugzilla.gnome.org/show_bug.cgi?id=737297
Fix testgtk.c when building for Wayland.

Fix wrong usage of GDK_WINDOWING_WAYLAND instead of
GDK_WINDOWING_X11 in test/testgtk.c.

Signed-off-by: Eric Le Bihan <eric.le.bihan.dev@free.fr>

https://bugzilla.gnome.org/show_bug.cgi?id=737363
inspector: life-cycle fixes

When closing the inspector before the main window, we must take
care to sever all signal connections and weak refs, otherwise
things will go bad when the window is closed later.
Updated Indonesian translation
gtk-demo: Don't create 2 main windows

Loading a builder file with a window leaves a ghost behind, since
windows need to be explicitly destroyed. Avoid that by using
gtk_builder_add_objects_from_resource.