Herbert Parentes Fortes Neto authored May 27, 2019 and Holger Levsen committed Aug 01, 2019

PEP 469 -- Migration of dict iteration code to Python 3
https://www.python.org/dev/peps/pep-0469/

And in diff_meta_data function:

    - a dict (tree1, tree2) to iterate
    - a dict (tree1_c, tree2_c) copy to 'del dict[key]'

To avoid RuntimeError or fail to iterate over all entries.

Herbert Parentes Fortes Neto authored Jul 21, 2019 and Holger Levsen committed Aug 01, 2019

And:

 - Add README* files
 - Add license.txt file
 - Add sphinx files conf.py, index.txt