work around syncprov interoperation issues; minor cleanup

servers/slapd/back-sql/add.c

servers/slapd/back-sql/bind.c

servers/slapd/back-sql/compare.c

servers/slapd/back-sql/delete.c

servers/slapd/back-sql/entry-id.c

servers/slapd/back-sql/init.c

servers/slapd/back-sql/modify.c

servers/slapd/back-sql/modrdn.c

servers/slapd/back-sql/proto-sql.h

servers/slapd/back-sql/rdbms_depend/pgsql/backsql_drop.sql

servers/slapd/back-sql/rdbms_depend/pgsql/testdb_drop.sql

servers/slapd/back-sql/search.c