Add a loop node with loop counter

For long term development of SF it might be interesting to add a loop node to the editor. This should help the guys and gals that keep asking for post processing capabilities.
The node could contain an enumerator to select between for and while loop.
Furthermore it should contain a loop counter, an end condition and of course an input node that contains the part of the graph that gets looped.

It might be interesting to add this feature for other purposes, too. For example to evaluate multiple light sources in a custom lighting shader.

In general loops are alot more programmer oriented stuff. So this feature might never make it into SF.