Automate some repetitive wrapping with macros

```
Wrapping overloaded methods is tedious, as is wrapping methods in a class
that needs to be derived in python code (method + default_method which are
basically always the same). 

This could be made easier and even a bit more readable by creating macros
to do it. Shouldn't be too hard.
```

Original issue reported on code.google.com by `jean.sebastien.guay13@gmail.com` on 10 Sep 2009 at 4:08
