flatpak (sat_wrapper): don't use packages from $HOME in PYTHONPATH to avoid conflicts: before this change, packages from ~/.local/lib/python2.7/site-packages when included, and this could conflict with the ones from Flatpak, resulting in unwanted side effects (e.g. OMEMO not available).

These icons follow the Tango project [1] guidelines and have been downloaded from openclipart.org [2]

Free to use.

[1] http://tango-project.org
[2] https://openclipart.org