linked list insertion/Simulator class

[Lori Flynn <lori@cse.ucsc.edu>]

Many thanks to Haobo Yu, he figured out the solution to my node variable
problem!

Next newbie question: How can I put a linked list data structure (a new
OTcl class I created) somewhere that the Simulator class can use it
(instead of upstream-node, a function within ns-2/tcl/mcast/ns-mcast.tcl).
However there must be one linked list per node.  

The node class doesn't need to access information within the linked list,
but the Simulator class must be able to access the correct linked list per
node id#. 

Many thanks in advance for all help!!
-Lori