Fix typo in previous commit
Count elements in arrays and handle generating handles, etc

* We now store the number of vertexes, texels, normals, etc
* We now create the vertex buffer data (and texel data buffer) using
OpenGL commands
Add back getters to Model.h

Later we should really remove them and move the code we're putting at
Object in Model, but fuck me
Getters for ModelArrays' data
Free up the GL buffers we allocate in ModelArrays
Add a Renderer and semi-stub implement Object rendering