cluster: migrate from worker.suicide

Replace it with worker.exitedAfterDisconnect. Print deprecation
message when getting or setting until it is removed.

PR-URL: https://github.com/nodejs/node/pull/3743
Fixes: https://github.com/nodejs/node/issues/3721


Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Сковорода Никита Андреевич <chalkerx@gmail.com>
Reviewed-By: Anna Henningsen <anna@addaleax.net>
Reviewed-By: Myles Borins <myles.borins@gmail.com>
Reviewed-By: Stephen Belanger <admin@stephenbelanger.com>