Fix the automatic creation of Refs scopes

In Scope.prototype.getRefs(), the ref scope that was created and appended as the parent of the scope chain, when a ref scope didn't already exist, was not actually a scope; it was a Scope.Refs object, which is meant to be the context object for a refs scope and not the Scope itself. This version fixes that creation to make it a Scope object.

This release also contains a cyclic dependency detection script that runs as part of the test process.