Bug 130492 Provide a method to serialize the report with library information.
Currently, when engine generate the report document file, the document does not contain any library information. That will cause many propblem on server side. Model should provide a method to serialize the report with library information to a stream so that the generated report document can contain all information that the report need.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/DesignElement.java
* <code>SemanticExcpetion</code>.
	 * 
	 * @return the validation error list.
	 */
	public List getErrors( )
	{
		if ( errors == null )
			return new ArrayList( );
		return errors;
	}
	/**
	 * Returns the identifier for locating element to user. This identifier
	 * string helps user locate this element in user interface. If this element
	 * has name defined, the name and element type are returned with the form
	 * "ElementType('Name')". Otherwise, locate the first container with name
	 * and generate the containment path with the form,
	 * "Container.Slot[Position]". If no container has name defined, "report" or
	 * container element type will be used as container's identifier, depending
	 * on whether this element is added into one report design.
	 * <p>
	 * For example,
	 * <ul>
	 * <li>report.body[0] - The first element in body slot
	 * <li>table("myTable") - The table named myTable
	 * <li>table("myTable").detail[0].cells[3] - The forth cell of the first
	 * row in table
	 * </ul>
	 * <p>
	 * Note: the localized name is used for element type and slot name.
	 *