Reviewed-by: chegar, alanb

Reviewed-by: alanb, dsamersoff

6964714: NetworkInterface getInetAddresses enumerates IPv6 addresses if java.net.preferIPvStack property set
Summary: User can disable ipv6 explicitly, have to check it
Reviewed-by: chegar, alanb

Reviewed-by: darcy, weijun

Summary: Make getIndex() and getByIndex() public. Required a name change in native code
Reviewed-by: alanb, chegar, michaelm