Python client: add compatibility with Python3

Signed-off-by: Tomas Sedovic <tomas@sedovic.cz>
Update README

Added license, updated the examples and the links in the readme. Also
switched to reStructuredText because we can then easilly include it as
`long_description` in `setup.py` and thus have it on PYPI.

Signed-off-by: Tomas Sedovic <tomas@sedovic.cz>
Update setup.py and MANIFEST.in

This fixes some of the outdated packaging metadata and makes the
package ready for distribution.

Signed-off-by: Tomas Sedovic <tomas@sedovic.cz>