WTF-389 Log an exception and terminate if widget config is invalid

If, on startup, a widget's positional configuration is invalid (ie:
cannot be displayed onscreen) then terminate the app and inform about
which widget is erroring

logger/log.go

@@ -52,7 +52,7 @@ func (widget *Widget) Refresh() {
 		return
 	}
 
-	widget.View.SetTitle(widget.Name)
+	widget.View.SetTitle(widget.Name())
 
 	logLines := widget.tailFile()
 	widget.View.SetText(widget.contentFrom(logLines))