Shivyc

Implemented several major new features, including:
* Function definition
* Typedef
* Cast operator
* Storage class specifiers
* Constant folding

Key features still missing are:
* Sizeof
* Initializers of aggregate types
* Better preprocessor support

Implemented compound types (arrays and structs) and relational comparison operators, along with some bugfixes and general improvements.

Fix README formatting.

Add new operators.

* Implemented proper uploading to PyPi.

Initial release of ShivyC as a Python 3 package.