Minor feature release for PYB11Generator.
- We have added better support for operators, with the option of explicitly providing the implementation (via PYB11implementation) for operators such as ``__mul__``, ``__add__``, etc.
- In such cases there is also a new decorator (PYB11operator) that should also be added to to such operator overloads.
- Updated the operator list to reflect Python 3 semantics, particularly with the addition of ``__truediv__`` and ``__floordiv__`` rather than the old ``__div__`` operation.