timeout: Only TERM signal sent to timeout is propagated to child

In contrast to GNU coreutils, uutils coreutils timeout is propagating only the TERM signal, e.g. INT signal just kills the timeout process.
Is this intentional ? 

Test:
```
$ timeout -v 365d sleep 100
```

```
$ pkill -INT timeout
```

Compare with TERM:

```
$ timeout -v 365d sleep 100
```

```
$ pkill -TERM timeout
```