Python type checker.

Provides decorators for type checking arguments and return values.

TODO

• add preparser to enable or sosomething
• add unit tests
• add Some optional type. Like Scala.
• add Any type for accepting any class.
• add property checker (or something, for objects)
• add list, tuple (abstract from there) checkers
• use inspect.isclass to enable type checking with examples
• add require_args for mandatory but untyped args