RFR: JDK-8194750, Console.readPassword does not save/restore tty settings

[Xueming Shen]

Hi,

Please help review the change for JDK-8194750.

issue: https://bugs.openjdk.java.net/browse/JDK-8194750
webrev: http://cr.openjdk.java.net/~sherman/8194750/webrev

*fix has been manually verified. No new auto-regression test added.

Thanks,
Sherman