python - be: Remove "conv" and some dead code.

Log Message:
-----------
Remove "conv" and some dead code.

The Datum_From* functions tended to be wasteful in the sense that normally they
would need to duplicate the PyPgObject's datum. It's best just to manage it
locally and duplicate a bit of code in only a few spots, rather than spend the
time on a superfluous datumCopy.

Additionally, "conv" was primarily taking up space as the remaining functions
may as well be moved into the files that use them.

(Hooray! Next "vague" file in sights is utils.[ch])

Modified Files:
--------------
    be:
        setup.py (r1.20 -> r1.21)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/setup.py.diff?r1=1.20&r2=1.21)
    be/include/pypg:
        heaptuple.h (r1.7 -> r1.8)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/include/pypg/heaptuple.h.diff?r1=1.7&r2=1.8)
        query.h (r1.8 -> r1.9)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/include/pypg/query.h.diff?r1=1.8&r2=1.9)
    be/include/pypg/type:
        object.h (r1.2 -> r1.3)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/include/pypg/type/object.h.diff?r1=1.2&r2=1.3)
    be/src:
        call.c (r1.8 -> r1.9)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/src/call.c.diff?r1=1.8&r2=1.9)
        heaptuple.c (r1.12 -> r1.13)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/src/heaptuple.c.diff?r1=1.12&r2=1.13)
        query.c (r1.17 -> r1.18)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/src/query.c.diff?r1=1.17&r2=1.18)
        tupledesc.c (r1.12 -> r1.13)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/src/tupledesc.c.diff?r1=1.12&r2=1.13)
    be/src/call:
        function.c (r1.9 -> r1.10)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/src/call/function.c.diff?r1=1.9&r2=1.10)
        pl.c (r1.16 -> r1.17)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/src/call/pl.c.diff?r1=1.16&r2=1.17)
        trigger.c (r1.8 -> r1.9)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/src/call/trigger.c.diff?r1=1.8&r2=1.9)
    be/src/type:
        object.c (r1.5 -> r1.6)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/src/type/object.c.diff?r1=1.5&r2=1.6)
        record.c (r1.7 -> r1.8)
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/src/type/record.c.diff?r1=1.7&r2=1.8)

Removed Files:
-------------
    be/include/pypg:
        conv.h
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/include/pypg/conv.h)
    be/src:
        conv.c
        (http://cvs.pgfoundry.org/cgi-bin/cvsweb.cgi/python/be/src/conv.c)