Support Clockwise and CounterClockwise rotation

[gbip]

When sending a speed command to the servomotor you can specify the direction of the rotation.

There is a bit that you need to set in order to force the servomotor to go in reverse direction. Take a look at the position bitfield from the datasheet :

In order to implement this, you need to :

1. Create a new enum to represent this parameter
2. Add it as a parameter in the sjog and ijog method from the builder pattern
3. Write some tests and document your code

[gbip]

cc @Terae