Re: Clarify libpq docs

Gavin Sherry wrote:
> The attached patch clarifies (or, rather, makes explicit) to readers
> how to handle memory management for char pointers returned by libpq
> functions. Although the sections on PQfinish(), PQclear() and
> PQfreemem() give an indication that all pointers returned by
> functions point to memory allocated in the underlying library, I
> thought it would be useful to make this clear.

Please don't put tabs in SGML files.  They don't have any real meaning
there.  Use spaces to indent.  (Normally, we indent code by 4 spaces
and SGML by 1 space.)