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
* returned. The level could be one of the following 3 options:
	 * <ul>
	 * <li>USER_LABEL: Only the first 3 steps can be visited, if not found,
	 * return null</li>
	 * <li>SHORT_LABEL: All the above 5 steps can be visited. This will ensure
	 * there will be a return value</li>
	 * <li>FULL_LABEL: Besides the return value of SHORT_LABEL, this option
	 * says we need to return additional information. To get this, every child
	 * element needs to overwrite this method</li>
	 * </ul>
	 * 
	 * @param module
	 *            the module
	 * @param level
	 *            the description level.
	 * @return the display label of this element.
	 */
	public String getDisplayLabel( Module module, int level )
	{
		String displayLabel = module.getMessage( getDisplayNameID( ) );
		if ( StringUtil.isBlank( displayLabel ) )
		{
			displayLabel = getDisplayName( );
		}
		if ( StringUtil.isBlank( displayLabel ) )
		{
			displayLabel = getNameForDisplayLabel( );
		}
		if ( level == USER_LABEL )
		{