python - lo: Add the encodings package back in.

Log Message:
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Add the encodings package back in.

However, it's a little different this time. bytea must be explicitly imported
to make it available to ''.encode() lookups. Aliases are not registered with
Python; rather, the user must import and map on an as needed basis.

Modified Files:
--------------
    lo:
        setup.py (r1.18 -> r1.19)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/setup.py.diff?r1=1.18&r2=1.19)

Added Files:
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    lo/postgresql/encodings:
        __init__.py (r1.3)

(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/postgresql/encodings/__init__.py?rev=1.3&content-type=text/x-cvsweb-markup)
        aliases.py (r1.1)

(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/postgresql/encodings/aliases.py?rev=1.1&content-type=text/x-cvsweb-markup)
        bytea.py (r1.4)

(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/postgresql/encodings/bytea.py?rev=1.4&content-type=text/x-cvsweb-markup)
        pbytea.py (r1.1)

(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/postgresql/encodings/pbytea.py?rev=1.1&content-type=text/x-cvsweb-markup)

Removed Files:
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    lo/postgresql/backend:
        __init__.py
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/lo/postgresql/backend/__init__.py)