pgsql: Include \password in the psql help.

Log Message:
-----------
Include \password in the psql help.

While at it, change the order of the documented options to be
alphabetically again.

Modified Files:
--------------
pgsql/src/bin/psql:
help.c (r1.122 -> r1.123)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/bin/psql/help.c?r1=1.122&r2=1.123)