Bug 136256 Enhance the message builder
Please see the spec attached in 133995 for detail.
UI/org.eclipse.birt.report.designer.ui.lib.explorer/src/org/eclipse/birt/report/designer/ui/lib/explorer/LibraryExplorerTreeViewPage.java
reportPreferenceNode.addPreferenceChangeListener( this );
			}
		}
		catch ( BackingStoreException e )
		{
			ExceptionHandler.handle( e );
		}
	}
	/**
	 * Creates the context menu
	 */
	private void createContextMenus( )
	{
		MenuManager menuManager = new LibraryExplorerContextMenuProvider( treeViewer );
		Menu menu = menuManager.createContextMenu( treeViewer.getControl( ) );
		treeViewer.getControl( ).setMenu( menu );				
		getSite( ).registerContextMenu( "#Pop up", menuManager, 
				getSite( ).getSelectionProvider( ) );
	}
	private String getTooltip( TreeItem item )
	{
		if ( item != null )
		{
			Object object = item.getData( );
			if ( object instanceof DataSourceHandle
					|| object instanceof DataSetHandle
					|| object instanceof ParameterHandle
					|| object instanceof ParameterGroupHandle
					|| object instanceof EmbeddedImageHandle )
			{