CSD Window won't unmaximize

[Danielle Foré]

For some unknown reason, (with GTK_CSD=1 in my .profile) Midori's maximize button is not updated and I'm unable to unmaximize.

[gue5t gue5t (gue5t)]

This is caused by midori_browser_window_state_event_cb having an incorrect signature; it should be (<https://developer.gnome.org/gtk3/unstable/GtkWidget.html#GtkWidget-window-state-event>) a gboolean callback and should return FALSE. I'll submit a branch later.