Script generation rate code and UI complete.

Updated the Generator.java and FlightEngine.java code to control script rate generation and ensure duplicate scripts are not sent. Implemented a simple token-bucket algorithm. Modified one method of IO.java from private to public as its functionality was exactly what was needed for some output filestream handling. Added a slider to the GUI to control the rate of script generation, modifying FlightGUI.pde (1 line) and UIComponents.pde in the process.