Blender Git Loki

Tomato Cycles: fix for memory overflow issue

This fixes memory overflow caused by creating render result every time
RenderResult is creating when updating sample and not being freed until
tile is fully rendered.

Solved in probably not best way -- RenderResult is being stored in
RenderBuffers, so it's creating only once.

This solves memory issues, but while was looking into this issue
discovered dramatic slowdown caused by samples update in some files
from mango svn.

Solving this slowdown is becoming first priority from now on.