Pipeline pixel updating and rendering

Render system by far takes the longest to update. Use 2 arrays so
we can update one and render another concurrently. It will display the
previously updated pixel map so the display is behind other systems
one cycle (insignificant).

It might improve perforamance a bit, unfortunately testeing found
rendering takes far longer (memory transfers) as without rendering
the world runs at ~14000+ cycles per second vs ~800 with rendering