Kaucher interval tracker

## Refactor progress
 
- [x] Iterator not needed.

- [x] `Map` function changed into a private function (`_map()`)

- [x] Added numpy support for unary functions

```python
x=Kaucher(2, 4)
np.sin(x)
np.exp(x)
```

- [x]  constructors `k`. Line 915


- [x] Refactored __equal__.


## Questions

- what will imposition and envelop mean for Kaucher intervals?

Oct 6th

- [ ] getter and setter