Demonstrations for JNI interface

To run the JNI demos:
  1. run make all
    which will create the shared libraries
  2. run make demo
    which will start up Vergil with the proper classpath and path
  3. For each model, select JNI -> Generate C Interface
    which will create the interface code in the jni directory and compile it.
    If you have problems compiling, see the JNIUtilities documentation for suggestions.
  4. Because of a bug that deletes all the relations, the easiest thing to do is to exit vergil and restart using make demo.
    An alternative is to close and reopen each model. Another alternative is to redraw the model
  5. Run each model