paginator-box: Stop using gtk_widget_set_child_visible()
This function is meant for widgets that don't need to be mapped along with
parent widget, not for scrolled out widgets. Additionally, using it causes
strange side effects with GtkOverlay window z-ordering. Stop using it and
instead track visiblity manually. Also, clarify the code a bit.
leaflet: Correctly handle 0 duration for swipe snap-back
swipe-tracker: Don't animate when the distance is 0.
Usually it makes sense to restrict the minimum animation duration. However,
if the progress already matches the end progress, it just causes a delay,
so skip it completely.
[ Julian Sparber ]
Keypad: Do not show allow typing + when only_digits is true.
The keypad shouldn't allow typing or show + when only_digits
is set to true. Therefore this adds the correct behavior.