[gi] add out annotations to pango layout API
[gi] add out annotations to pango layout API

https://bugzilla.gnome.org/show_bug.cgi?id=642593

kari-lentz/alpha-pango,kari-lentz/alpha-pango,danny-ku/pango,Distrotech/pango,kari-lentz/alpha-pango,danny-ku/pango,Distrotech/pango,Distrotech/pango,danny-ku/pango,kari-lentz/alpha-pango