Add code comments

[tony]

We need to add some code comments/pydoc for the module so we know what's coming from where.

Also: use API doc to show off the internals with http://www.sphinx-doc.org/en/stable/ext/autodoc.html

[hellysmile]

Comments were written maybe 5+ years ago and they are ugly, I agree.

Any changes is more then welcome. As for me I think I do not enough time to fix them in nearest future