[C++-sig] Abstract class instances to-python conversion

[Valentin Perrelle]

> You could use the reload() function in python 2.7 or imp.reload() in python 3. It takes a module object as argument.
Thanks. However it wouldn't reset to the initial state in the general 
case. All modules needs to be unloaded. I don't know a safe way to it 
yet. I'm just sure i want to do it in c++ not in Python.

I've just found that the call of Py_Finalize with Boost.Python is a 
known issue, already discussed on this mailing list and that the manual 
says not to call it : 
http://www.boost.org/doc/libs/1_47_0/libs/python/doc/tutorial/doc/html/python/embedding.html