Remove/clear JOptionPanes raised during tests

I've noticed that occasionally option panes are raised and hang around during tests. If we are to run tests unattended these need to be non-blocking, but regardless, its still disconcerting to see the dialogs hanging around whilst other things happen during the test.

It would be good if there were a standard (GUI class independent) model for raising JOptionPanes that tests could use to clear, or even introspect any optionpanes that were raised during tests.

An example that disconcerted me was a dialog titled 'PDB Web-service error' that contained text starting wth '====== PDB Rest Client RunTime Error ========' - followed by an unintelligible error raised by the SOLR service.