Bug 124430 [Smoke][Regression][RCP]Library explorer keep gray even you add library file in Preferences.
Description: Library explorer keep gray even you add library file in Preferences. Steps to reproduce: 1. New several library files and add them through Window-->Preferences menu. 2. New a report and open Library Explorer view. Expected result: Library files display inside it. Actual result: It is gray with nothing inside. I cannot find add button in Library Explorer to add a library file,either.
UI/org.eclipse.birt.report.designer.ui.lib.explorer/src/org/eclipse/birt/report/designer/ui/lib/explorer/LibraryExplorerView.java
* @see #doCreatePage
	 */
	protected void doDestroyPage( IWorkbenchPart part, PageRec pageRecord )
	{
		IPage page = pageRecord.page;
		page.dispose( );
		pageRecord.dispose( );
	}
	/**
	 * Returns the active, important workbench part for this view.
	 * <p>
	 * When the page book view is created it has no idea which part within the
	 * workbook should be used to generate the first page. Therefore, it
	 * delegates the choice to subclasses of <code>PageBookView</code>.
	 * </p>
	 * <p>
	 * Implementors of this method should return an active, important part in
	 * the workbench or <code>null</code> if none found.
	 * </p>
	 * 
	 * @return the active important part, or <code>null</code> if none
	 */
	protected IWorkbenchPart getBootstrapPart( )
	{
		IWorkbenchPage page = getSite( ).getPage( );
		if ( page != null )
		{
			return page.getActiveEditor( );
		}
		return null;