". . . the debarred party's pleadings may and usually should be taken into account for the purposes of defining and confining the ambit of the real dispute; and, for example, admissions may be taken as rendering proof of the admitted matters unnecessary. However, that is not to say that the proceeding party is entitled to seek adjudication of the debarred party's case: only to adjudication of its own case, and only then insofar as the court considers requisite in order to determine whether to grant relief and in what terms."