pgsql-server: Add PGETC (for pg_service.conf) and PGLOCALE (for locale

Log Message:
-----------
Add PGETC (for pg_service.conf) and PGLOCALE (for locale dir)
environment variable processing to libpq.

The patch also adds code to our client apps so we set the environment
variable directly based on our binary location, unless it is already
set. This will allow our applications to emit proper locale messages
that are generated in libpq.

Modified Files:
--------------
    pgsql-server/doc/src/sgml:
        libpq.sgml (r1.155 -> r1.156)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/doc/src/sgml/libpq.sgml.diff?r1=1.155&r2=1.156)
    pgsql-server/src/backend/main:
        main.c (r1.85 -> r1.86)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/backend/main/main.c.diff?r1=1.85&r2=1.86)
    pgsql-server/src/bin/initdb:
        initdb.c (r1.34 -> r1.35)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/bin/initdb/initdb.c.diff?r1=1.34&r2=1.35)
    pgsql-server/src/bin/pg_controldata:
        pg_controldata.c (r1.16 -> r1.17)

(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/bin/pg_controldata/pg_controldata.c.diff?r1=1.16&r2=1.17)
    pgsql-server/src/bin/pg_ctl:
        pg_ctl.c (r1.5 -> r1.6)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/bin/pg_ctl/pg_ctl.c.diff?r1=1.5&r2=1.6)
    pgsql-server/src/bin/pg_dump:
        pg_dump.c (r1.372 -> r1.373)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/bin/pg_dump/pg_dump.c.diff?r1=1.372&r2=1.373)
        pg_dumpall.c (r1.35 -> r1.36)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/bin/pg_dump/pg_dumpall.c.diff?r1=1.35&r2=1.36)
        pg_restore.c (r1.57 -> r1.58)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/bin/pg_dump/pg_restore.c.diff?r1=1.57&r2=1.58)
    pgsql-server/src/bin/pg_resetxlog:
        pg_resetxlog.c (r1.19 -> r1.20)

(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/bin/pg_resetxlog/pg_resetxlog.c.diff?r1=1.19&r2=1.20)
    pgsql-server/src/bin/psql:
        startup.c (r1.94 -> r1.95)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/bin/psql/startup.c.diff?r1=1.94&r2=1.95)
    pgsql-server/src/bin/scripts:
        clusterdb.c (r1.8 -> r1.9)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/bin/scripts/clusterdb.c.diff?r1=1.8&r2=1.9)
        createdb.c (r1.10 -> r1.11)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/bin/scripts/createdb.c.diff?r1=1.10&r2=1.11)
        createlang.c (r1.11 -> r1.12)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/bin/scripts/createlang.c.diff?r1=1.11&r2=1.12)
        createuser.c (r1.12 -> r1.13)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/bin/scripts/createuser.c.diff?r1=1.12&r2=1.13)
        dropdb.c (r1.11 -> r1.12)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/bin/scripts/dropdb.c.diff?r1=1.11&r2=1.12)
        droplang.c (r1.10 -> r1.11)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/bin/scripts/droplang.c.diff?r1=1.10&r2=1.11)
        dropuser.c (r1.10 -> r1.11)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/bin/scripts/dropuser.c.diff?r1=1.10&r2=1.11)
        vacuumdb.c (r1.8 -> r1.9)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/bin/scripts/vacuumdb.c.diff?r1=1.8&r2=1.9)
    pgsql-server/src/include:
        port.h (r1.39 -> r1.40)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/include/port.h.diff?r1=1.39&r2=1.40)
    pgsql-server/src/interfaces/libpq:
        fe-connect.c (r1.271 -> r1.272)

(http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/interfaces/libpq/fe-connect.c.diff?r1=1.271&r2=1.272)
        fe-misc.c (r1.106 -> r1.107)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/interfaces/libpq/fe-misc.c.diff?r1=1.106&r2=1.107)
    pgsql-server/src/port:
        path.c (r1.16 -> r1.17)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql-server/src/port/path.c.diff?r1=1.16&r2=1.17)