RFR: 8154238: Drop code to support Windows XP in windows socket impl

[Alan Bateman]

On 18/04/2016 10:45, Chris Hegarty wrote:
>
> The changes look fine.
>
> Maybe the bug description should be updated a before pushing,
> it looks like it affects only legacy networking code and not
> NIO. Maybe "... and async channels" ?
The changes to the NIO code look okay but probably should be split into 
their own issue for tracking purposes.

-Alan