docs: Documentation fixes for CoglMatrix
docs: Documentation fixes for CoglMatrix

Clean up the references, the docbook tags, and the style to fit in
with the rest of the API references for Cogl and Clutter.

Distrotech/clutter,jigpu/clutter,jigpu/clutter,djdeath/clutter-android,djdeath/clutter-android,GNOME/clutter,djdeath/clutter,GNOME/clutter,djdeath/clutter,spatulasnout/clutter,collects/clutter,kerrickstaley/clutter-vala,Distrotech/clutter,heysion/clutter-clone,ebassi/clutter,ebassi/clutter,heysion/clutter-clone,rkudiyarov/clutter_osx,djdeath/clutter-android,Distrotech/clutter,jigpu/clutter,rkudiyarov/clutter_osx,spatulasnout/clutter,heysion/clutter-clone,ebassi/clutter,collects/clutter,GNOME/clutter,djdeath/clutter-android,heysion/clutter-clone,GNOME/clutter,djdeath/clutter-android,Distrotech/clutter,nobled/clutter,kerrickstaley/clutter-vala,GNOME/clutter,djdeath/clutter,rkudiyarov/clutter_osx,djdeath/clutter,jigpu/clutter,spatulasnout/clutter,jigpu/clutter,collects/clutter,Distrotech/clutter,ebassi/clutter,kerrickstaley/clutter-vala,djdeath/clutter-multithreaded,djdeath/clutter-multithreaded,dlespiau/clutter,dlespiau/clutter,Distrotech/clutter,spatulasnout/clutter,djdeath/clutter,collects/clutter,dlespiau/clutter,djdeath/clutter-multithreaded,rkudiyarov/clutter_osx,collects/clutter,ebassi/clutter,djdeath/clutter-multithreaded,spatulasnout/clutter,nobled/clutter,kerrickstaley/clutter-vala,nobled/clutter,jigpu/clutter,djdeath/clutter,heysion/clutter-clone