pgsql: plpython improvements: 1) named parameters additionally to

Log Message:
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plpython improvements:

    1) named parameters additionally to args[]
    2) return composite-types from plpython as dictionary
    3) return result-set from plpython as list, iterator or generator

Hannu Krosing
Sven Suursoho

Modified Files:
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    pgsql/src/pl/plpython:
        plpython.c (r1.77 -> r1.78)
        (http://developer.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpython/plpython.c.diff?r1=1.77&r2=1.78)