added tests
better to string
fixed bug in depth first adapter case for loop detection where a !node type was added to a node list
Major upgrade til version 1.4.0

* update for extensions where the apply method now detects if the visitor is an extended version or not. If not it searched to find a super class method in the base visitor that it may visit.
* added THIS field in adaptors, this should be used when apply methods are called that should progress in the same visitor. This is to be used for extensions that thus can handle new additions before returning to the this visitor.
* many other small fixes.
added deploy notes