Add Flash Telnet link to index page

Add External Programs link to left side nav bar
"External Programs" will allow users to execute external programs via their web browser, using the bundled flash telnet client (fTelnet).  This is accomplished via RLogin, which of course must be enabled for the feature to work.  A flash socket policy server is also required in order for the flash control to open a socket connection to the server.
The new feature is disabled by default, and may be enabled by modifying modopts.ini