RFR 8162521, java/net/Authenticator/B4933582.sh fails intermittently with BindException

[Felix Yang]

Hi,

   please review the following patch. The code was converted from shell 
script to plain Java. Since it is by-design to bind on a prior-used 
port, add a few of re-tries for possible BindException.

Bug:

    https://bugs.openjdk.java.net/browse/JDK-8162521

Webrev:

     http://cr.openjdk.java.net/~xiaofeya/8162521/webrev.00/

Thanks,
Felix