python - be: Add namespace interfaces.

Log Message:
-----------
Add namespace interfaces.

New namespace type for providing access to the namespace's contents and
information. Function, Type, Relation, etc. methods are used for element type
selectivity.

Type, Function, and Operator are known to be working, others still need testing.

Modified Files:
--------------
be:
setup.py (r1.5 -> r1.6)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/setup.py.diff?r1=1.5&r2=1.6)
be/src:
module.c (r1.7 -> r1.8)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/src/module.c.diff?r1=1.7&r2=1.8)
prime.py (r1.4 -> r1.5)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/src/prime.py.diff?r1=1.4&r2=1.5)

Added Files:
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be/src:
namespace.c (r1.1)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/src/namespace.c?rev=1.1&content-type=text/x-cvsweb-markup)
be/include/pypg:
namespace.h (r1.1)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/include/pypg/namespace.h?rev=1.1&content-type=text/x-cvsweb-markup)