(question of existence of prescriptive easement or easement acquired by adverse possession submitted to special master via state law which issued finding of prescriptive easement in favor of defendant; trial court affirmed; on further review, appellate court noted that issue of permissive use was involved, but special master failed to consider state statute specifying that “permissive possession cannot be foundation of a prescription until an adverse claim and actual notice to the other party”; trial court award of prescriptive easement in favor of defendant vacated and special master must reconsider prior decision).