Added 'new' option to open options to have it open a new stream even
Added read_can and read_pro (in analogy to read_dsv) to allow uniform
Added definition of multifile predicate portray/1 as false.
Fixed bug in table_index in handling 0-ary predicates. Also added compiler
Fixed bug in handling structure unification when the structures are $BOX$,
Added predicate log_ith_new/3.
Updated documentation of table_index directive for improved