pgsql: Adjust lookup of client-side profile files (.pgpass and so on) as

Log Message:
-----------
Adjust lookup of client-side profile files (.pgpass and so on) as per
discussion on pgsql-hackers-win32 list.  Documentation still needs to
be tweaked --- I'm not sure how to refer to the APPDATA folder in
user documentation.

Modified Files:
--------------
    pgsql/doc/src/sgml:
        libpq.sgml (r1.174 -> r1.175)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/libpq.sgml.diff?r1=1.174&r2=1.175)
        release.sgml (r1.317 -> r1.318)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/release.sgml.diff?r1=1.317&r2=1.318)
    pgsql/doc/src/sgml/ref:
        pg_dumpall.sgml (r1.47 -> r1.48)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/pg_dumpall.sgml.diff?r1=1.47&r2=1.48)
        psql-ref.sgml (r1.127 -> r1.128)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/psql-ref.sgml.diff?r1=1.127&r2=1.128)
        vacuumdb.sgml (r1.34 -> r1.35)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/ref/vacuumdb.sgml.diff?r1=1.34&r2=1.35)
    pgsql/src/backend/libpq:
        README.SSL (r1.3 -> r1.4)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/backend/libpq/README.SSL.diff?r1=1.3&r2=1.4)
    pgsql/src/bin/psql:
        input.c (r1.42 -> r1.43)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/input.c.diff?r1=1.42&r2=1.43)
        startup.c (r1.108 -> r1.109)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/startup.c.diff?r1=1.108&r2=1.109)
    pgsql/src/interfaces/libpq:
        fe-connect.c (r1.296 -> r1.297)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/libpq/fe-connect.c.diff?r1=1.296&r2=1.297)
        fe-secure.c (r1.63 -> r1.64)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/interfaces/libpq/fe-secure.c.diff?r1=1.63&r2=1.64)
    pgsql/src/port:
        path.c (r1.47 -> r1.48)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/port/path.c.diff?r1=1.47&r2=1.48)