Relaxed type checking concerning boolean arguments in class constructors

and __call__ methods so that not only True and False but also various
other boolean expressions (e.g., 0, 1, and None) are accepted.

source/blender/freestyle/intern/python/BPy_Convert.cpp

@@ -326,7 +326,7 @@ PyObject * BPy_ChainSilhouetteIterator_from_ChainSilhouetteIterator( ChainSilhou
 //==============================
 
 bool bool_from_PyBool( PyObject *b ) {
-	return (b == Py_True || PyInt_AsLong(b) != 0);
+	return PyObject_IsTrue(b) != 0;
 }
 
 IntegrationType IntegrationType_from_BPy_IntegrationType( PyObject* obj ) {