Vuze/BiglyBT Swing emulation layer for NDT Applet.

This is a simple shim to allow running the NDT Applet code
with minimal modifications.
From BiglyBT MLab plugin:
Github rev e927dca, Aug. 18, 2018.
From https://github.com/BiglySoftware/BiglyBT-plugin-mlab
This is for Tcpbw100 from NDT 3.6.2b;
not sufficient to compile Tcpbw100 from 3.7.0.2,
changes to follow.
License: GPLv2.