[C++-sig] [python] base::get_override() exception set

[Trigve Siver]

Hi,
when calling get_override() method while trying to find python overload and 
overload is not found exception in python is set. This is because 
PyObject_GetAttrString() is used for retrieving the attribute. If attribute is 
not found, PyObject_GetAttrString() set the exception. This is using python 3.1. 
I've created ticket https://svn.boost.org/trac/boost/ticket/4701 with patch. 
Could anyone look at this?

Thanks

Trigve