Jsonconversion

Updated build process

Updated dependency deprecation and moved to python3

The constructor of `JSONObjectEncoder` is now more generic in terms of accepted `kwargs`.

Should now be installable for all 2.6.* and 2.7.* Python interpreters

* Convert `README.md` to `README.rst`
* add `__version__` information
* Update `setup.py`
* set correct `url`
* add `download_url`
* set correct `version`
* add `classifiers`
* parse `README.rst` for `long_description`
* add missing copyright header
* correct `python_requires` string