Private node chat client/server application.

Usage:
Use node to run staticServer.js on any private or public server.
If your server is private, (behind your firewall), be sure to port-forward port #81 .
Launch two or more client apps -->> http:your-server-IP:81
The client application prompts for both a user name and a passcode.
The passcode is used as a private encription key. It must match on each
client.

The encription is a minimized version of ... /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - /
/ Block TEA (xxtea) Tiny Encryption Algorithm (c) Chris Veness 2002-2016 /
/ - www.movable-type.co.uk/scripts/tea-block.html MIT Licence /
/ /
/ Algorithm: David Wheeler & Roger Needham, Cambridge University Computer Lab /
/ http://www.cl.cam.ac.uk/ftp/papers/djw-rmn/djw-rmn-tea.html (1994) /
/ http://www.cl.cam.ac.uk/ftp/users/djw3/xtea.ps (1997) /
/ http://www.cl.cam.ac.uk/ftp/users/djw3/xxtea.ps (1998) /
/ - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */

If the clients passcodes don't match, the application works but will only show mangled text.
Click the Help-link for a help screen. The list does not scroll. To trim the list size,
click on any list item to delete it.