Hash: add sha256-96 and sha512-96

IPSec uses them and some versions of OpenSSH use them (even though RFC6668 makes no mention of them)
> Could you elaborate on your suggestion?

Yes. Instead of overwriting hashData() I probably would have replaced testHash() as follows:
```
/**
* @dataProvider hashData()
*/
public function testHash($message, $longResult)
{
    $this->assertHashesTo($this->getInstance(), $message, substr($longResult, ...));
}
```
or even
```
/**
* @dataProvider hashData()
*/
public function testHash($message, $longResult)
{
    parent::testHash($message, substr($longResult, ...));
}
```
because this does not involve any handling of meaningless array indexes and such.