Enable pl/python to return records based on multiple OUT params

attached is a patch which enables plpython to recognize function with
multiple OUT params as returning a record

py=# create or replace function addsub( in i1 int, in i2 int,
py=# out o1 int, out o2 int) as
py=# $$
py$# return i1 + i2, i1-i2
py$# $$ language plpythonu;
CREATE FUNCTION
py=#
py=# select * from addsub(1,2);
o1 | o2
----+----
3 | -1
(1 row)

This version is quite rough, though passes tests here.

I will clean it up more during commitfest.

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Hannu Krosing http://www.2ndQuadrant.com
PostgreSQL Scalability and Availability
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