nativenet: Port nativenet for netdev

To test this run

```
export BOARD=native
SENDER=0 make -C tests/netdev/ all flash && SENDER=1 make -C tests/netdev/ all flash && make -C tests/netdev/ test
```

Depends on #1492:

```
* #1733
| * #1732
|/
| * #1731
|/
* #1492
```