Make contrib/isn pass the opr_sanity sanity checks: add missing

Make contrib/isn pass the opr_sanity sanity checks: add missing
commutator operators, and mark hash-opclass members as oprcanhash.
This is a pretty ugly, brute-force solution, but it seems that getting
rid of all these redundant-looking operators would require some tweaks
in the core operator-resolution code to behave nicely, and I'm not
willing to risk that just before RC1.