Use a NbtkTextureCache to cache the presence icons
Use a NbtkTextureCache to cache the presence icons

This necessitates removing and reinserting the ClutterTexture each time since
the NbtkTextureCache can only return a new texture. If we can make it just
return the CoglHandle then that should be the awesome.

meego-netbook-ux/anerley,meego-netbook-ux/anerley