Subject: [PATCHES] More psql and libpq patches

Well..these would be the last patches until the release (I hope)...
I ran the regression tests while watching psql under purify, and it did
not leak even one byte.

In this patch:

* Plugged a major leak when PSQL reads files for input (either through
  \i options or through -f option)
* Fixed the one remaining leak in PSQL in not clearing PGresult *results
  everywhere it is supposed to. (Thanks Tymm)
* Fixed A small leak in PSQL not clearing all the PGsettings correctly.
* A not-so-obvious (but small) leak in Libpq when PQsetdb fails for any
  reason.
* Added \n to some Libpq error messages to make them easier to digest..
* Finally, added /* PURIFY */ comment to some of the code indicating
  the reason for why it was added/changed...for future developers.