Review request for 8016531: jconsole-plugin script demo does not work with nashorn

[A. Sundararajan]

Please review http://cr.openjdk.java.net/~sundar/8016531/

This fix was contributed by Andreas Rieber ( arieber ).

I combined another one fix by Andreas for :

      7023754 : Jconsole javascript plugin demo throws exception on 
window.print

as well as that fix is to make a class 'public' and the issue is related 
anyway.

Thanks
-Sundar