hostid patch

[Max Bowsher]

Chris January wrote:
> *Not* tested on anything other than Windows XP.
>
> Adds gethostid function to Cygwin. Three patches: one for Cygwin, one for
> newlib and one for w32api.
> If I've done anything wrong let me know and I'll try to fix it.

"diff -u" format patches are preferred.

Newlib patches need to go to the newlib list. (In this case, probably after
the Cygwin ones have been applied.)

Max.