fix($compile): set the iteration state before linking

This issue was introduced in 0d053946f3ef7546de804a5f2224baa514d28156.
The state for each row has to be set up *before* linking.

The cloneFn (the function passed into $transclude) is called *before* actual linking and thus it is enough to update the state inside the cloneFn callback.
fix($compile): bound transclusion to correct scope

Nested isolated transclude directives.

This improves/fixes the fix in c39e441398f80635c294cb435db9c980a2ab8f74.

See the added unit test: The template inside ng-if should be bound to the
isolate scope of `iso` directive (resp. its child scope). Not to a child of
the root scope. This shows the issue with ng-if. It’s however problem with
other directives too.

Instead of remembering the scope, we pass around the bound parent transclusion.