This is part of a broader cleanup of some of the experimental Cogl API.
One of the reasons for this particular rename is to reduce the verbosity
of using the API. Another reason is that CoglVertexArray is going to be
renamed CoglAttributeBuffer and we want to help emphasize the
relationship between CoglAttributes and CoglAttributeBuffers.
To allow us to have gobject properties that accept a CoglMatrix value we
need to register a GType. This adds a cogl_gtype_matrix_get_type function
that will register a static boxed type called "CoglMatrix".
This adds a new section to the reference manual for GType integration
functions.
So we can keep track of the experimental progress of Cogl 2.0 features
this adds a standalone Cogl 2.0 Reference Manual which doesn't cover
the deprecated 1.x symbols and removes the need for a "Cogl
experimental API" chapter since those sections now make up the main
table of contents.
