The original definitions were leaving no room for cross-type operators,
so queries that compared a column of one type against something of a
different type were not taking advantage of the index.  Fix by making
the opfamilies more like the ones for Btree, and include a few
cross-type operator classes.

Catalog version bumped.

Per complaints from Hubert Lubaczewski, Mark Wong, Heikki Linnakangas.