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/command/TemplateCommand.java
* @param prop
	 *            the definition of property
	 *            <code>REF_TEMPLATE_PARAMETER_PROP</code> in template
	 *            elements
	 * @param value
	 *            the new value to set
	 * @throws PropertyValueException
	 *             throws exception if it refers non-exsiting template parameter
	 *             definition or a wrong type definition
	 */
	public void checkProperty( ElementPropertyDefn prop, Object value )
			throws PropertyValueException
	{
		if ( value == null )
			return;
		
		
		
		if ( ( element instanceof ReportItem || element instanceof TemplateReportItem )
				&& DesignElement.REF_TEMPLATE_PARAMETER_PROP.equals( prop
						.getName( ) ) )
		{
			assert value instanceof ElementRefValue;
			if ( ( (ElementRefValue) value ).getElement( ) == null )
			{