The IDE's ExitDialog uses a rather unfriendly exception dialog when there are
exceptions saving files that had unsaved data when the user tried to exit the
IDE (for example, if the file in question has become read only, or or course,
any other I/O problem).

Since this dialog invokes each (unsaved) dataobject's SaveCookie.save()
directly, throwing an IOException from the cookie's save() implementation seems
to be the only way inform the ExitDialog that the file was in fact NOT saved
(and thus keep it in the list of files that are unresolved.)  I would prefer
that either there is a way for me to provide a nice message in my save()
implementation for cases like this (I can put up the message, but I still have
to rethrow the exception for ExitDialog to not remove it from the box which
means the user will see the exception box), or better, for the ExitDialog code
to handle such cases more gracefully than it does now.

Note also that for Java files, they do provide a nice message for cases like
this, but the result is that after the failure to save the file, the IDE exits
immediately and throws away the unsaved changes w/o giving the user another
chance to fix the problem.