Adding empty domains implementation until we can implement and test it
Merge #667 r=@johnnyman727: Adding empty domains implementation until we can implement and test it

Empty Domain implementation until we can implement and test a legitimate one.
Buffer.fill with strings
Merge #671 r=@johnnyman727: Buffer.fill with strings

Related to #666

This is the Node.js version `0.10.x` implementation of `Buffer.fill`. 

@johnnyman727 we can merge this for now and then when Node.js `0.12.x` is released we'll merge the next one that I'll submit in 5 minutes.