“Here, Mr Beesley’s [the builder] conduct, although not identifiably criminal, consisted of positive deception in matters integral to the planning process… and was directly intended to and did underline the regular operation of that process. Mr Beesley would be profiting directly from this deception if the passing of the normal four-year period for enforcement which he brought about by the deception were to entitle him to resist enforcement. The apparently unqualified statutory language cannot in my opinion contemplate or extend to such a case”