The prototype for printw is wrong

The declaration for `printw` is

```
printw(str::T)
```

This is completely wrong. `printw` is like the C function `printf` so the first argument is the format string and it takes a bunch of other arguments, the objects to be formatted. The prototype should be something like

```
printw(str::T,objs::Any...)
```

but I have no idea if this fits with the C declaration...
