Expose CoglFramebuffer (and a few other Cogl classes) for introspection
This is a small merge request that is a pre-requisite for the larger explicit framebuffer management work. It exposes CoglFramebuffer, its implementations, and CoglPipeline for introspection. It also fixes a bug where CoglOffscreen is not correctly identified as a CoglFramebuffer implementation.
Edited by Georges Basile Stavracas Neto