GUI interface for simulation properties configuration

[jordi]

Implement a GUI interface (Swing, GTK,...) to load simulation properties and retrieve the output.

Goal: To exist a possibility to avoid completely command line executions.

GUI Operation guidelines:

1. Start the GUI interface.
2. Select the test to simulate.
3. Verify/Change default simulation properties. May be can exist the possibility to save at disk with a different filename.
4. Run the simulation. It would be good to appear a console line to see the current output of the simulation, as well as to save the same output into a certain filename (configured at the end of the process in step 3).
5. Start the necessary output visualizer (existing Yield or Pajek).
6. Restart the same simulation or restart from step 2.

Jordi