deprecate multiplication orders:

vector * matrix
 vector *= matrix
 vector * quaternion
 vector *= quaternion 

Use the reverse order instead, enable WITH_ASSERT_ABORT in cmake to promote the warnings into errors.

source/blender/python/mathutils/mathutils.h

@@ -108,4 +108,6 @@ int _BaseMathObject_WriteIndexCallback(BaseMathObject *self, int index);
 int mathutils_array_parse(float *array, int array_min, int array_max, PyObject *value, const char *error_prefix);
 int mathutils_any_to_rotmat(float rmat[3][3], PyObject *value, const char *error_prefix);
 
+int column_vector_multiplication(float rvec[4], VectorObject *vec, MatrixObject *mat);
+
 #endif /* MATHUTILS_H */