Reported by kaystrobach in comment:ticket:551:3:
it's the same for feedback, dashboard, api, ... -> all are hardcoded ... :(, if seen this after deeactivating the feedbackplugin
I'll commit your patch for #999 separately.
The other half of this ticket is to suppress a disabled plugin's widgets in the dashboard layout.
in (why did the trac not automatically put the message here?)
note that if ones disables all plugins, then go to the dashboard, adds a widget, all previously added widgets from disabled plugins will then be lost on dashboard layout save.