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
ISlotDefn slotDefn = getDefn( ).getSlot( slotId );
		assert slotDefn != null;
		if ( !slotDefn.canContain( defn ) )
			return false;
		
		
		
		String name = defn.getName( );
		if ( ReportDesignConstants.TEMPLATE_DATA_SET.equals( name )
				|| ReportDesignConstants.TEMPLATE_REPORT_ITEM.equals( name )
				|| ReportDesignConstants.TEMPLATE_ELEMENT.equals( name ) )
			return true;
		if ( getSlot( slotId ).getCount( ) > 0
				&& !slotDefn.isMultipleCardinality( ) )
			return false;
		return true;
	}
	/**
	 * Checks whether the element to insert can reside in the given module.
	 * 
	 * @param module
	 *            the root module of the element to add
	 * @param slotID
	 *            the slot ID to insert
	 * @param element
	 *            the element to insert
	 * @return false if the module is a library and the element to insert is a
	 *         template element or its content is a template element; or the
	 *         container is report design and slot is component slot and the
	 *         element to insert is a template element or its content is a