Bug 167450 [DataBinding] Get rid of bind support factory magic
I finally realized that we don't need that other magic factory. I'll move fillBindSpecDefaults() and the methods it calls (createConverter, createValidator etc) to a new class DefaultBindSpec. Clients who want default validators and converters created for them just create a DefaultBindSpec as opposed to a (rather empty) BindSpec. I will also move the early type checking into DefaultBindSpec to make it optional as well.
bundles/org.eclipse.jface.databinding/src/org/eclipse/jface/databinding/viewers/UnorderedTreeNode.java
isStale = willBeStale;
            
            contentProvider.changeStale(isStale? 1 : -1);
        }
    }
    
    /**
     * @return
     */
    public boolean isStale() {
        return isStale;
    }
    /**
     * Returns true if the viewer should show a plus sign for expanding this 
     * node. 
     * 
     * @return
     */
    public boolean shouldShowPlus() {
        if (children == null) {
            return true;
        }
        if (!listeningToChildren && !prefetchEnqueued) {
            prefetchEnqueued = true;
            contentProvider.enqueuePrefetch(this);
        }
        return !listeningToChildren || hasPendingNode || !children.isEmpty();
    }
    
    /**