Fix inherited methods in the Miller class

[hakonanes]

The Miller class inherits methods and properties from Vector3d and thus also Object3d. Currently, these methods and properties aren't handled properly:

Vector3d

• empty()
• from_polar()
• get_circle()
• get_nearest() (should raise NotImplementedError)
• rotate()
• xvector()
• yvector()
• zero()
• zvector()
• perpendicular

Object3d

• get_random_sample()
• squeeze()
• stack()

It's not critical to get this in as a patch release, releasing it in 0.10 is fine.