pgsql: Fix numericlocale psql option when used with a null string and

Log Message:
-----------
Fix numericlocale psql option when used with a null string and latex and troff
formats; a null string must not be formatted as a numeric. The more exotic
formats latex and troff also incorrectly formatted all strings as numerics
when numericlocale was on.

Backpatch to 8.1 where numericlocale option was added.

This fixes bug #5355 reported by Andy Lester.

Modified Files:
--------------
    pgsql/src/bin/psql:
        describe.c (r1.238 -> r1.239)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/describe.c?r1=1.238&r2=1.239)
        print.c (r1.122 -> r1.123)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/print.c?r1=1.122&r2=1.123)
        print.h (r1.44 -> r1.45)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/print.h?r1=1.44&r2=1.45)