Python-joy

* Added setup.py to release a pypi package
* Improved the docs

* Fixed inconsistencies in rendering caused due to a bug in cloning the node (34)

* Improved the repeat tranformation and fixed a couple of bugs that were introduced due to these improvements
* Added new functions `combine`, `color` and `random`
* Added `polyline` shape (tx abhinavxd)
* Added `polygon` shape
* Added `as_dict` method to Shape to be able to serialize the shapes to JSON
* Added lowercase function names for transformations.
* Fixed the issues with `line` function

* Fixed a typo that causing the y coordinate to be initialized to the value of argument `x` instead of `y`.

* Added lowercase functions for shapes with simpler API

* Made the y value grow upwards, just like the classical cartisian
coordinate system learn in the high school