API changes to ZOOM. Functions for setting options returns int, rather

API changes to ZOOM. Functions for setting options returns int, rather
than void, so we have a way to flag unknown options. ZOOM_resultset_sort1
has become "the" ZOOM_resultset_sort. (and old ZOOM_resultset_sort is
removed). ZOOM_connection_scan1 removed. The generic scan is
ZOOM_connection_scan and the ZOOM_connection_scan_pqf is a handy short-hand
taking a PQF string as argument.