Update gtk-doc 'Since' field for cogl_texture_multiple_rectangles
Update gtk-doc 'Since' field for cogl_texture_multiple_rectangles

The function has been backported to the 0.8 branch so it will also be
available in Clutter 0.8.6

gcampax/cogl,Distrotech/cogl,djdeath/cogl-android,djdeath/cogl,collects/cogl,djdeath/cogl-android,Distrotech/cogl,gcampax/cogl,collects/cogl,djdeath/cogl-android,Distrotech/cogl,spatulasnout/cogl,gcampax/cogl,djdeath/cogl,spatulasnout/cogl,djdeath/cogl,Distrotech/cogl,gcampax/cogl