Automatically catch AbortRequest at n-th parent

I am replacing a parent node and then visiting the new one explicitly. In order to not visit all children twice, I have to call `this.abort();`.
Catching the exception however is a bit cumbersome as I'd have to surround many `traverse` calls in the `visit...` methods of my visitor object with try-catch clauses and re-throw the exception if applicable.

Could you implement this in PathVisitor? I was thinking of something like this:
```
// jump up 2 levels
var abortLevels = 2;
this.abort(abortLevels);
```
The abort request should then automatically be canceled after stepping up n levels.
`abortLevels = 0;` would equivalent to `return false;` in this case.

Start by reading PathVisitor's abort behavior and the traverse calls in the visitor methods. Trace how an abort request propagates while replacing and revisiting a parent node. Done means abort(n) is canceled after stepping up n levels, while abort(0) behaves like return false.

Written by the indexing model from the issue text.