X-Newest header not supported in HEAD request

[majewsky]

Object does not provide for a way to set the X-Newest: true header. Refer to the API reference for details.

I'm aware that I can give extra headers to ObjectOpen, ObjectGet etc., but I'm dealing with large objects and therefore cannot afford downloading the entire file.

[ncw]

Perhaps factor Object into ObjectHead which does take some headers?

Would you like to send a PR for this?