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
IValidationListener,
		IPreferenceChangeListener
{
	
	
	private ILibraryProvider libraryProvider;
	private IEclipsePreferences reportPreferenceNode;
	private TreeViewer treeViewer;
	/**
	 * Creates the tree view
	 * 
	 * @param parent
	 *            the parent
	 */
	protected TreeViewer createTreeViewer( Composite parent )
	{
		treeViewer = new TreeViewer( parent, SWT.MULTI
				| SWT.H_SCROLL
				| SWT.V_SCROLL );
		configTreeViewer( );
		initPage( );
		return treeViewer;
	}
	/**
	 * Configures the tree viewer.
	 */
	protected void configTreeViewer( )