Re: jsonb and nested hstore

* The jsonb_hash_ops non-default GIN opclass is broken. It has its own

idiosyncratic notion of what constitutes containment, that sees it
only return, say, jsonb arrays that have a matching string as their
"leftmost" element (if we ask it if it contains within it another
array with the same string). Because of the limited number of
indexable operators (only @>), I'd put this opclass in the same
category as GiST in terms of my willingness to forgo it for a release,
even if it did receive a loud applause at pgConf.EU. Again, it might
be some disparity between the opertors as they existed in hstore2 at
one time, and as they exist in the core code now, but I doubt it, not
least since the regression tests didn't pick this up, and it's such a
basic thing. Perhaps Oleg and Teodor just need to explain this to me.