- open OptionDialog via File/Options menu; close it

- open OptionDialog via Version Control / Show History / Compare Revisions / Options... button

==> the dialog appears parented to the app frame insted of the history dialog frame. 

The reason for this is that OptionDialog is created only once and retains the attachment to the initial parent frame.  We need to create the modal OptionDialog anew each time, but perhaps keep all these beans and objects used by it.  Or even better, perhaps we could redesign the options subsystem and get rid of the reflection altogether.