Guide to alternative expected files:

plpython_error_2.out		Python 2.2, 2.3, 2.4
plpython_error.out			Python 2.5, 2.6

plpython_unicode.out		any version, when server encoding != SQL_ASCII; else ...
plpython_unicode_2.out		Python 2.2
plpython_unicode_3.out		Python 2.3, 2.4
plpython_unicode_5.out		Python 2.5, 2.6
