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
* are of type Listener. Created only when needed.
	 */
	protected ArrayList listeners = null;
	/**
	 * Values for non-intrinsic property values. The contents are of type
	 * Object.
	 */
	protected Map propValues = new HashMap( );
	/**
	 * Definitions for user-defined properties. Contents are of type
	 * UserPropertyDefn.
	 */
	protected HashMap userProperties = null;
	/**
	 * Support for inheritance. Represents the resolved or unresolved element
	 * that this element extends.
	 */
	protected ElementRefValue extendsRef = null;
	/**
	 * Inverse of the extends relationship: parent-->derived. Very few elements
	 * are extended, so we create this list only when needed.
	 */
	protected ArrayList derived = null;
	/**
	 * The unique ID assigned to this element when it is added to the design.
	 * Allows web applications to refer to the element by ID.
	 */
	protected long id = NO_ID;
	/**
	 * Cached element definition. Cached for speed since the definition cannot