[ns] ns with tcltk-8.3 and gcc-2.96

[John Heidemann <johnh@ISI.EDU>]

We've now gotten ns to pass all tests with tcltk-8.3 and gcc-2.96.
(This is what will ship with Redhat 7.0.)

Previously we'd had some reports of success:
<http://www.isi.edu/nsnam/archive/ns-users/webarch/2000/msg02360.html>
and some of only partial success
<http://www.teltec.dcu.ie/~murphys/ns-work/notes/ns-tcl-831.html>.

To get ns to build clealy you need to update tclcl to a snapshot dated
after 16-Aug-00.

In addition, we're working with Don Libes to make tcl-debug-1.10
available to support tcltk-8.3.  To get ns to build with that
you'll need an ns snapshot taken after 16-Aug-00 as well.

Thanks to Sean Murphy for trying out tcltk-8.3 earlier and posting his
tips.

I don't have any performance comparisions of ns with tcltk-8.3
vs. 8.0.  If anyone happens to do some, please let us know.

   -John Heidemann