Starting the setup for builtin types for rendering. This will allow
the engine to be easier to use for beginners while still offering
great modularity and functionality. The builtin namespace is
intended to simplify mesh loading and rendering. It should
eventually offer pre-made shaders to simplify the rendering of the
builtin types. Possibly in the future, it could have partially
setup scenes/application to simplify scene/application building
Finally got a 3D cube to be rendered. While doing it, fixed a
bug in MeshFactory that caused it to allocate the incorrect amount
of memory for each mesh.
Now batches are actually batches.
Also added the MeshFactory class.
Drawing modes are now specified with DrawMode instead of the
GLenum. Renderables must be specified with a draw mode.
