cogl-pango-display-list: Use CoglPrimitive instead of CoglVertexBuffer
cogl-pango-display-list: Use CoglPrimitive instead of CoglVertexBuffer

When rendering text through a VBO, CoglPangoDisplayList now uses the
CoglPrimitive API instead of CoglVertexBuffer. CoglVertexBuffer is
just a layer on top of the attribute buffer API anyway so it should be
slightly faster.

https://bugzilla.gnome.org/show_bug.cgi?id=656303

Reviewed-by: Robert Bragg <12e9293ec6b30c7fa8a0926af42807e929c1684f@linux.intel.com>

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