#6 Add nwn-io.jar to the nwn-tools.jar internal classpath

[Paul Speed]

nwn-tools.jar pulls in all of the other lib jars that
it needs in its manifest's classpath. It does not pull
in the nwn-io.jar. Normally this doesn't matter if you
run the generated scripts but it makes manual running
harder on non-windows platforms since my setup scripts
only generate scripts for windows right now.