ExecSupport, when showing an exception and prompting to
reconfigure, does not take into account ErrorManager localized
annotations. Ditto CloneableEditorSupport.notifyModified.

Affects anyone who throws ErrorManager-localized IOException from
Executor.execute(); nothing useful is shown in the dialog box. I think use of
ErrorManager annotations now supercedes the interim hack of checking whether the
localized message differs from the base message.

Ideally only getAnnotation would be needed in code like this, and NbErrorManager
would actually autocreate localized-message annotations from exceptions whose
localized message was in fact distinct.