Define Compose.__name__

Should composed functions have a `__name__` attribute?

```Python
In [1]: def add(x, y):
    return x + y
   ...: 

In [2]: def inc(x):
    return x + 1
   ...: 

In [3]: from toolz import compose

In [4]: f = compose(inc, add)

In [5]: f.__name__
Out[5]: 'inc_o_add'
```

If so how should we define that name?  here I join with `_o_`.  Suggestions welcome.