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
* Part of: The containment system.
	 * 
	 * @return Returns the container.
	 */
	public DesignElement getContainer( )
	{
		return container;
	}
	/**
	 * Caches the child-to-container relationship. The caller must have
	 * validated that the relationship is valid.
	 * <p>
	 * Part of: The containment system.
	 * 
	 * @param obj
	 *            the container to set
	 * @param slot
	 *            the slot within the container where this element resides
	 */
	public void setContainer( DesignElement obj, int slot )
	{
		container = obj;
		containerSlotID = slot;
	}
	/**
	 * Gets the property data for either a system-defined or user-defined
	 * property.
	 * <p>
	 * Part of: Property system and user-defined property system
	 *