https://wiki.gnome.org/Design/OS/Typography

Popovers aren't direct children of the widget they point to, but yet
they act as children of it, so do the same with state propagation,
so the flags that propagate across the hierarchy reach popovers too.

Anytime ::grab-notify comes across, the popover visibility and GTK+
grab ownership are checked, so the popover is hidden when it loses
the GTK+ by any reason.

Previously we did a semi-successful job at ignoring it. Unfortunately
this job was bad enough that we could lose the direction.

We still allow passing in the enum values, because we want code like
this to work:
  set_state_flags (get_state_flags() | SOME_FLAGS)

Since we don't have a setting for this, hardcode the value
for now.

This reverts commit 7a411eb6.
This also makes gedit external tools manager to crash

Install Gtk's GOptionGroup in GApplication just before commandline
arguments are parsed.

Do not call _column_autosize() if there is no treeview set yet.

https://bugzilla.gnome.org/show_bug.cgi?id=723637

Heavy duty can prevent this idle function from being called before
the window is destroyed, so make sure that the source is removed
when the window is finalized.

https://bugzilla.gnome.org/show_bug.cgi?id=723771

Otherwise, calling gtk_widget_grab_focus() on a widget when the
popover send ::closed won't work.

This signal is emitted when the popover is dismissed either through
API or user interaction, somewhat more friendly than connecting to
::unmap.

This is a test commit for hook checks.