Bug 136241 [regression]Preview template in web viewer and pdf didn't get correct effect.
Description: Preview template items in web viewer and pdf didn't get correct effect. Steps to reproduce: 1. Create template items. 2. Preview in Web Viewer and pdf. Expected result: Same effect as in html. Actual result: In web viewer, see only blank box. In pdf, blank page.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
* of this element.
	 * 
	 * @param element
	 *            The potential ancestor.
	 * @return True if the given element is an ancestor of this element, false
	 *         otherwise.
	 */
	public boolean isKindOf( DesignElement element )
	{
		DesignElement e = this;
		while ( e != null )
		{
			if ( e == element )
				return true;
			e = e.getExtendsElement( );
		}
		return false;
	}
	/**
	 * Determines if any elements extend this element.
	 * 
	 * @return True if the element is extended, false if not.
	 */
	public boolean hasDerived( )
	{
		return derived != null && derived.size( ) > 0;
	}
	/**
	 * Returns the optional display name. Note: set the display name by calling
	 * the {@link #setProperty( String, Object )}method.