python - lo: Add iri, pgpass, and environ modules.

Log Message:
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Add iri, pgpass, and environ modules.

Relocate environment extraction into environment to increase flexibility. ie,
consider command that make use of non-standard options that still want to get
the Postgres-environment configuration. Also, this provides a point of extension
across applications that make use of the environ module.
Implement PGSERVICE handling.

Extend the number of options and remove the environment defaults which are now
handled in the environ module. Notable additions, -I/--iri and --pg-service
options. Remove -P and -S for process and socket; these are unlikely to be used
frequently enough to justify consuming a short option.

Add a pgpass module that provides parsing and lookup facilities that match the
logic described in the PostgreSQL documentation.

Include some mostly naive unit tests. Currently, it only validates basic
functionality for environ and option, but goes into greater detail for iri.

Modified Files:
--------------
lo:
LICENSE (r1.1 -> r1.2)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/LICENSE.diff?r1=1.1&r2=1.2)
setup.py (r1.15 -> r1.16)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/setup.py.diff?r1=1.15&r2=1.16)
lo/postgresql/backend:
typoid.py (r1.1 -> r1.2)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/postgresql/backend/typoid.py.diff?r1=1.1&r2=1.2)
lo/postgresql/encodings:
bytea.py (r1.1 -> r1.2)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/postgresql/encodings/bytea.py.diff?r1=1.1&r2=1.2)
lo/postgresql/utility:
config.py (r1.2 -> r1.3)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/postgresql/utility/config.py.diff?r1=1.2&r2=1.3)
version.py (r1.1 -> r1.2)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/postgresql/utility/version.py.diff?r1=1.1&r2=1.2)
lo/postgresql/utility/client:
option.py (r1.7 -> r1.8)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/postgresql/utility/client/option.py.diff?r1=1.7&r2=1.8)
lo/test:
encodings.py (r1.1 -> r1.2)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/test/encodings.py.diff?r1=1.1&r2=1.2)

Added Files:
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lo/postgresql/utility/client:
environ.py (r1.1)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/postgresql/utility/client/environ.py?rev=1.1&content-type=text/x-cvsweb-markup)
iri.py (r1.1)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/postgresql/utility/client/iri.py?rev=1.1&content-type=text/x-cvsweb-markup)
pgpass.py (r1.1)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/postgresql/utility/client/pgpass.py?rev=1.1&content-type=text/x-cvsweb-markup)
lo/test:
pg_service.conf (r1.1)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/test/pg_service.conf?rev=1.1&content-type=text/x-cvsweb-markup)
utility_client.py (r1.1)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/test/utility_client.py?rev=1.1&content-type=text/x-cvsweb-markup)