pgsql: PL/Python DO handler Also cleaned up some redundancies between

Log Message:
-----------
PL/Python DO handler

Also cleaned up some redundancies between the primary error messages and the
error context in PL/Python.

Hannu Valtonen

Modified Files:
--------------
    pgsql/doc/src/sgml:
        plpython.sgml (r1.43 -> r1.44)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/plpython.sgml?r1=1.43&r2=1.44)
    pgsql/src/include/catalog:
        catversion.h (r1.576 -> r1.577)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h?r1=1.576&r2=1.577)
        pg_pltemplate.h (r1.12 -> r1.13)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_pltemplate.h?r1=1.12&r2=1.13)
    pgsql/src/pl/plpython:
        Makefile (r1.35 -> r1.36)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpython/Makefile?r1=1.35&r2=1.36)
        plpython.c (r1.135 -> r1.136)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpython/plpython.c?r1=1.135&r2=1.136)
    pgsql/src/pl/plpython/expected:
        plpython_error.out (r1.9 -> r1.10)
        (http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpython/expected/plpython_error.out?r1=1.9&r2=1.10)

Added Files:
-----------
    pgsql/src/pl/plpython/expected:
        plpython_do.out (r1.1)

(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpython/expected/plpython_do.out?rev=1.1&content-type=text/x-cvsweb-markup)
    pgsql/src/pl/plpython/sql:
        plpython_do.sql (r1.1)

(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpython/sql/plpython_do.sql?rev=1.1&content-type=text/x-cvsweb-markup)