lilyglyphs: Python 2 deprecation

[Werner LEMBERG]

On the TeXLive mailing list, Norbert Preining <address@hidden>, one
of the maintainers of TeXLive posted the following today.

  With the end of 2019, Python2 will be deprecated and not receive any
  security updates.  Most distributions will throw out Python2
  completely.  (Don't ask me about my opinion on the whole Py2/Py3
  mess ...)

  We have quite a lot of scripts in TeX Live that are Python2 only,
  and we should seriously do some work on getting that fixed, rather
  soon.

  I have started a list of packages/scripts I found that require python,
  and tried to check which version they need, see below list.
 
  If you are the maintainer of any of these packages, and still are using
  Python2, please try to update to Python3 as soon as possible.

    ...
    lilyglyphs/
      py2 only
      lilyglyphs/lily-glyph-commands.py
      lilyglyphs/lily-image-commands.py
      lilyglyphs/lily-rebuild-pdfs.py
      lilyglyphs/lilyglyphs_common.py
    ...

This package is written by Urs Liska <address@hidden>, who is
quite busy these days.  In case you have experience with Python 2 to 3
conversion, please help produce a new version!


    Werner