Patch for psql startup clarity

Kind people,

Here's a minor patch for psql and related files that turns instances
of

 \? for help on internal slash commands

into

\? for help on internal slash (i.e. psql) commands

I think this makes it clearer exactly what \? does and how it's
different from \h

Cheers,
D
--
David Fetter david@fetter.org http://fetter.org/
phone: +1 510 893 6100    cell: +1 415 235 3778