If there is no secondary text, then the primary text is just a message,
not a title, and should not use title style.
This partially reverts 1e3ec7c1f9. The
message dialog nown looks like it used to in GTK 3. However, it's still
styled only using a style class rather than using pango markup, as in
GTK 3.
Fixes#3509
Instead, use a new title style class to let
themes influence title formatting. Note that
the theme style will be overridden if the
application uses markup for presentation,
such as <b> or <i>.
The skip-taskbar, skip-pager and urgency hints were
only ever implemented for X11, and are not very useful
with modern desktops. Relegate the functionality to
x11 backend api, and drop the GtkWindow api.
The position child property is problematic, since it
requires us to emit notification for all children when
inserting a child early in the list of children.
Remove the property from all ui files.
We used to always make the labels in message dialogs selectable,
which is a bit problematic wrt. to keynav - the label can
unexpectedly 'turn blue', which irritates some people.
With the new gtk-keynav-use-caret setting, we can now only
make the labels selectable when it is required for accessibilty
reasons.
This subdirectory gets in the way when integrating the inspector
build more fully with GTK+, and does not really add anything.
Just move everything one level up.
