bug21003: python-tutorial/python-tutorial-40.html references AG 4.2

tests added    : no
tests run      : no (docs built)
performance    : no change
release note   : none

I changed the document to use 4.x which won't go out of date.

I also removed some long ago <!-- ... --> commented code.

Change-Id: If445bad52cd7804ae0f92bec41e479f762271a2b
Reviewed-on: https://gerrit.franz.com:9080/3925
Reviewed-by: Ahmon Dancy <dancy@franz.com>
Reviewed-by: John O'Rourke <jor@franz.com>
Tested-by: Kevin Layer <layer@franz.com>