The symbol name for cogl_vertex_buffer_draw_elements was wrong so it
ended up with no documentation. The name for the vertex attribute was
incorrect in cogl_vertex_buffer_add.
This function was renamed a while ago in the .c file from
cogl_vertex_buffer_draw_range_elements but the corresponding .h and
doc/reference/cogl changes weren't made.
For convenience it is now valid to avoid a seperate call to
cogl_vertex_buffer_submit() and assume that the _draw() calls will do this
for you (though of course if you do this you still need to ensure the
attribute pointers remain valid until your draw call.)
This hides a number of internal structs and enums from the docs, and moves
some functions to more appropriate sections as well as misc description
updates (mostly for the vertex buffer api)
This better reflects the fact that the api manages sets of vertex attributes,
and the attributes really have no implied form. It is only when you use the
attributes to draw that they become mesh like; when you specify how they should
be interpreted, e.g. as triangle lists or fans etc. This rename frees up the
term "mesh", which can later be applied to a concept slightly more fitting.
E.g. at some point it would be nice to have a higher level abstraction that
sits on top of cogl vertex buffers that adds the concept of faces. (Somthing
like Blender's mesh objects.) There have also been some discussions over
particle engines, and these can be defined in terms of emitter faces; so some
other kind of mesh abstraction might be usefull here.
