Bug 218360 [Servicability] Fix places that pop up message dialogues under ISafeRunnable
bundles/org.eclipse.jface/src/org/eclipse/jface/preference/PreferenceDialog.java
*/
	void clearSelectedNode() {
		setSelectedNodePreference(null);
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.jface.window.Window#close()
	 */
	public boolean close() {
		
		
		SafeRunnable runnable = new SafeRunnable(){
			/* (non-Javadoc)
			 * @see org.eclipse.core.runtime.ISafeRunnable#run()
			 */
			public void run() throws Exception {
				List nodes = preferenceManager.getElements(PreferenceManager.PRE_ORDER);
				for (int i = 0; i < nodes.size(); i++) {
					IPreferenceNode node = (IPreferenceNode) nodes.get(i);
					node.disposeResources();
				}
				
			}
			
			/* (non-Javadoc)
			 * @see org.eclipse.jface.util.SafeRunnable#handleException(java.lang.Throwable)
			 */
			public void handleException(Throwable e) {
				super.handleException(e);