fdo#59728: Fix encoding of .py files as UTF-8 for Python 3
fdo#59728: Fix encoding of .py files as UTF-8 for Python 3

...where it could default to something like CP 1252 instead on Windows, while
keeping backwards compatibility for now with running under Python 2 (where
things apparently worked well with the original code).

Change-Id: I0ddd06771a36e1cd2cc2ce78abd8bd667db7778f

JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core,JurassicWordExcel/core