Currently, the unref() method does not remember any state
if called before the server's handle has been created. This
commit adds state to track calls to ref() and unref().
PR-URL: https://github.com/iojs/io.js/pull/897
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: Brendan Ashworth <brendan.ashworth@me.com>
