Add menu bar to frame

[JoeyBB91]

It might be nice to implement a menu bar, so the user doesn't have to exit the application by closing the window.

We could add a File menu to implement these menu items:

• Reset (allows user to restart simulation);
• Exit (allows user to exit without closing window);

Another possibility would be for us to implement a Help menu to implement this item:

• About...

[JoeyBB91]

Almost done! Still missing the Reset function.

[JoeyBB91]

Menu is implemented! This issue can be closed.