Request a reasonable minimum size for the scale, but
let the mediacontrols drop both labels and scale when
space is at a premium.

Take child-visible into account in addition to visible
when deciding whether a child should contribute to layout.

When droppable is > 0, omit the child from the
minimum size, and hide droppable children when
allocating less space than fits all children.

Add a layout child for GtkBoxLayout, with a droppable
property that determines whether an item can be dropped
if there is lack of space.

widget-factory: Enable page transitions by default

See merge request GNOME/gtk!1777

No need to make this an easter egg.

GtkFilechooserWidget: prevent oblivious selection of file

See merge request GNOME/gtk!1688

mediacontrols: Use tabular figures for time and duration

See merge request GNOME/gtk!1774

In particular, this prevents gtk4-widget-factory from jumping every
second.