Problem with the tree model

[NicoKiaru]

We get a lot of errors (which can be ignored in most cases) like this:

Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 9 >= 6
	at java.util.Vector.elementAt(Vector.java:479)
	at javax.swing.tree.DefaultMutableTreeNode.getChildAt(DefaultMutableTreeNode.java:245)
	at javax.swing.tree.DefaultTreeModel.nodesWereInserted(DefaultTreeModel.java:313)
	at sc.fiji.bdvpg.scijava.services.ui.SourceFilterNode.lambda$insert$1(SourceFilterNode.java:168)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
	at java.awt.EventQueue.access$500(EventQueue.java:97)
	at java.awt.EventQueue$3.run(EventQueue.java:709)
	at java.awt.EventQueue$3.run(EventQueue.java:703)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)
Exception in thread "AWT-EventQueue-0" java.lang.ArrayIndexOutOfBoundsException: 10 >= 6
	at java.util.Vector.elementAt(Vector.java:479)
	at javax.swing.tree.DefaultMutableTreeNode.getChildAt(DefaultMutableTreeNode.java:245)
	at javax.swing.tree.DefaultTreeModel.nodesWereInserted(DefaultTreeModel.java:313)
	at sc.fiji.bdvpg.scijava.services.ui.SourceFilterNode.lambda$insert$1(SourceFilterNode.java:168)
	at java.awt.event.InvocationEvent.dispatch(InvocationEvent.java:311)
	at java.awt.EventQueue.dispatchEventImpl(EventQueue.java:758)
	at java.awt.EventQueue.access$500(EventQueue.java:97)
	at java.awt.EventQueue$3.run(EventQueue.java:709)
	at java.awt.EventQueue$3.run(EventQueue.java:703)
	at java.security.AccessController.doPrivileged(Native Method)
	at java.security.ProtectionDomain$JavaSecurityAccessImpl.doIntersectionPrivilege(ProtectionDomain.java:74)
	at java.awt.EventQueue.dispatchEvent(EventQueue.java:728)
	at java.awt.EventDispatchThread.pumpOneEventForFilters(EventDispatchThread.java:205)
	at java.awt.EventDispatchThread.pumpEventsForFilter(EventDispatchThread.java:116)
	at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThread.java:105)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:101)
	at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:93)
	at java.awt.EventDispatchThread.run(EventDispatchThread.java:82)

There is a sync issue between the model and the GUI. That's a major rewrite which is needed.