Use search-bar styling for the nautilus query editor

https://bugzilla.gnome.org/show_bug.cgi?id=709863
highcontrast: Drop g_type_init()

No longer needed with modern GLib.
Reduce the vertical padding around the notebook tabs

Make the tabs a bit slimmer and more symmetric.

https://bugzilla.gnome.org/show_bug.cgi?id=711425
gnome-bluetooth: Make the PIN label large