num-args

Guys, we need to target python3 here, not python2.  As far as I can tell, in python3, these c functions are supposed to take 2 args, not 3, i.e. in
```
static PyObject * compress16i_8i(PyObject * self, PyObject * args, PyObject * keywds)
```
we should really have, I think,
```
static PyObject * compress16i_8i(PyObject * args, PyObject * keywds)
```
