migration. Stabilized a lot of the code for C++ -> Python conversion. Added the correct rich comparison operator and tested it. Corrected 'dupplicate' typo and changde to __copy__ for Python API.
From now on, when a set should be output (PySet_Type), it is given as a list (PyList_Type). The reason is that it doesn't really matter what we bring back to the Python interpreter. The set is guaranteed in memory on the C++ side.
For the CurvePoint class, the userdata variable is not yet ported (and will probably available as a list or a dictionary). The CurvePoint implementation works except for the initialization from other CurvePoints: somehow, the inner variables don't seem to be correctly handled. I do not know if it is a bug in Freestyle or if the CurvePoint object's state is correct for my test case. CurvePoint needs more testing.
