If you want to include the library (like batik-svgpathparser-1.7.jar) in the SweetHome3D.jar itself to get a Java application you can launch with a double-click, you should add it to the list of libraries that need to be extracted at program launch, like in SweetHome3DBootstrap.
If the library you use contains classes with callbacks, you should also add the first part of their package(s) in applicationPackages array.