Support to new driver

It should be compatible with previous versions. Tell me if you think that I've coded something the bad way
This whole thing can be just the same.

First of all, you are using `digitalWrite` on PWM pin. Secondly, it doesn't really matter what the value on the direction pin is when we are stopping the motor.

Thus, you can use 

```
digitalWrite(_dir, LOW);
analogWrite(_pwm,0);
```

In both cases.