Discardable dialogs

Some dialogs in EiffelStudio include a check box labeled "Do not show me again". If you select it, the dialog will not be shown the next time the same situation occurs. The "dialogs" sub-category of "Interface" in the preferences lists the state of those discardable dialogs: a boolean preference is associated with each of them. The window will be shown if and only if the corresponding preference is set to True.