Issue 243 - general idea

[Danny van der Rijn <dannyv@tibco.com>]

I didn't actually put 243 into the draft of 242 as I said I might.  243 
would look very similar - split forEach into serialForEach and 
parallelForEach, and moving the required scope-child of parallelForEach 
into the parent element.  remove the requirement for serialForEach to 
have a scope child.