NOW we're really getting to the part where this module is more awesome
than DBD::Pg.
(When I started working on this module I was expecting that the Postgres
binary protocol would send jsonb in a binary format as well and that I'd
be duplicating parts of the JSON parser/formatter to make that work, but
it turns out that Postgres just uses plain json for exchange. Saves me
some trouble, I guess)
I liked the Perl implementation of transactions, but managing state
between Perl and C is a bit cumbersome, so I've moved the whole thing
into C.
Also added a few statement configuration methods that currently don't do
anything yet.
