7026287: Implement New I/O API (NIO.2) demo/sample

[Rickard Bäckman]

Some sample code implementing a pretty basic chat server using the new 
asynchronous APIs in JDK7.

The suggested sample: 
http://cr.openjdk.java.net/~rbackman/7026287/7026287-1/webrev/ 
<http://cr.openjdk.java.net/%7Erbackman/7026287/7026287-1/webrev/>

Thanks
/Rickard