python - be: Move IST interfaces to PL.

Log Message:
-----------
Move IST interfaces to PL.
With that, the dependency on Postgres error to Python exception conversion
routines. So, link the pl against error.c.

Add STATE tags to installed filenames, giving project versioning to be, rather
than being solely based on python and postgres versions.
So, $libdir/pl/python24-dev.so and postgresl.backend.interface.teop.dev-v80.*
STATE being "dev".

Modified Files:
--------------
be:
setup.py (r1.7 -> r1.8)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/setup.py.diff?r1=1.7&r2=1.8)
be/include/pypg:
externs.h (r1.5 -> r1.6)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/include/pypg/externs.h.diff?r1=1.5&r2=1.6)
be/src:
error.c (r1.5 -> r1.6)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/src/error.c.diff?r1=1.5&r2=1.6)
globals.c (r1.5 -> r1.6)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/src/globals.c.diff?r1=1.5&r2=1.6)
module.c (r1.9 -> r1.10)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/src/module.c.diff?r1=1.9&r2=1.10)
pl.c (r1.8 -> r1.9)
(http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/src/pl.c.diff?r1=1.8&r2=1.9)