Checks needed when updating a widget to be a singleton about owf-framework

[colemanserious]

From a usage perspective... what should then occur if it is in use?

Options that come to mind:

• allow it to be set as singleton, but provide the user with a dashboard in this state some better message and way to remove the extra instance / contact an administrator
• give the administrator a way to find those dashboard instances and work with users.. (presumably there's a reason to make it a singleton)
• not allow the administrator to set that widget instance up as singleton, but instead create a new widget definition, and potentially mark the existing one as not usable in new dashboards...

Also, presumably it being in background, as well as singleton, just makes it harder to discover the offending widget?