Remove assumptions in resource_manager that resources are pointers
Fill m_Textures during cap, and store tex dimension & # MSAA samples
Since the debug layer complains for me, respect GL_MAX_VERTEX_ATTRIBS

* I need to respect the GL_MAX_* values all over the render state, but the
  other things don't complain so I can ignore it for now :).
First implementation of initial contents for GPU dirty textures