pgsql: Python 3 support in PL/Python Behaves more or less unchanged

Log Message:
-----------
Python 3 support in PL/Python

Behaves more or less unchanged compared to Python 2, but the new language
variant is called plpython3u. Documentation describing the naming scheme
is included.

Modified Files:
--------------
pgsql:
configure (r1.662 -> r1.663)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/configure?r1=1.662&r2=1.663)
pgsql/config:
python.m4 (r1.16 -> r1.17)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/config/python.m4?r1=1.16&r2=1.17)
pgsql/doc/src/sgml:
installation.sgml (r1.332 -> r1.333)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/installation.sgml?r1=1.332&r2=1.333)
plpython.sgml (r1.41 -> r1.42)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/doc/src/sgml/plpython.sgml?r1=1.41&r2=1.42)
pgsql/src:
Makefile.global.in (r1.259 -> r1.260)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/Makefile.global.in?r1=1.259&r2=1.260)
pgsql/src/include/catalog:
catversion.h (r1.558 -> r1.559)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/catversion.h?r1=1.558&r2=1.559)
pg_pltemplate.h (r1.9 -> r1.10)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/include/catalog/pg_pltemplate.h?r1=1.9&r2=1.10)
pgsql/src/pl/plpython:
Makefile (r1.34 -> r1.35)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpython/Makefile?r1=1.34&r2=1.35)
plpython.c (r1.133 -> r1.134)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpython/plpython.c?r1=1.133&r2=1.134)
pgsql/src/pl/plpython/expected:
README (r1.4 -> r1.5)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpython/expected/README?r1=1.4&r2=1.5)
plpython_test.out (r1.13 -> r1.14)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpython/expected/plpython_test.out?r1=1.13&r2=1.14)
plpython_trigger.out (r1.6 -> r1.7)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpython/expected/plpython_trigger.out?r1=1.6&r2=1.7)
pgsql/src/pl/plpython/sql:
plpython_test.sql (r1.9 -> r1.10)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpython/sql/plpython_test.sql?r1=1.9&r2=1.10)
plpython_trigger.sql (r1.4 -> r1.5)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpython/sql/plpython_trigger.sql?r1=1.4&r2=1.5)

Added Files:
-----------
pgsql/src/pl/plpython/expected:
plpython_types_3.out (r1.1)
(http://anoncvs.postgresql.org/cvsweb.cgi/pgsql/src/pl/plpython/expected/plpython_types_3.out?rev=1.1&content-type=text/x-cvsweb-markup)