Add event for completion of flush operation after setChild

[René Schöne]

In case, a trace-receiver were to react to events of type INC_FLUSH_ATTR by potentially calling other attributes or accessing the AST, a bad state could result. Therefore, it would be good to have a new event signalling the completion of notification of depedencies resulting from setting a new value for some token. This way, such a receiver could react upon this completion event.

[René Schöne]

I’ve just opened pull request !18 as a proposal for resolving this

[Jesper Öqvist]

As the pull request !18 was merged I assume this should be closed. If this is an error please re-open.