python - lo: Add and expand some doc-strings.

Log Message:
-----------
Add and expand some doc-strings.

Modified Files:
--------------
lo/postgresql/utility/client:
iri.py (r1.1 -> r1.2)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/postgresql/utility/client/iri.py.diff?r1=1.1&r2=1.2)