Add function for quote_qualified_identifier?

Hi hackers,

I note that we currently expose the usefulness of the quote_identifier
function to the user with quote_ident(text).

Is there any reason we shouldn't do the same with quote_qualified_identifier?

We could just add a quote_qualified_ident(text, text) ... it would
make forming dynamic queries more convenient in databases that use
multiple schemas.

Clearly a DBA could just create this function himself in SQL (and it
wouldn't be difficult), but is that a good reason not to have it in
our standard set of functions?

Would be happy to cook up a patch for this.

Cheers,
BJ