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
* @param propName
	 *            The name of the property to lookup.
	 * @return The property definition, or null, if the property is undefined.
	 */
	public ElementPropertyDefn getPropertyDefn( String propName )
	{
		
		ElementPropertyDefn prop = (ElementPropertyDefn) getDefn( )
				.getProperty( propName );
		if ( prop == null )
			prop = getUserPropertyDefn( propName );
		return prop;
	}
	/**
	 * Validates that the given property name is either a system-defined or
	 * user-defined property.
	 * <p>
	 * Part of: Property system.
	 * 
	 * @param propName
	 *            The name of the property to validate.
	 * @throws PropertyNameException
	 *             If the property is undefined.
	 */
	void validatePropertyName( String propName ) throws PropertyNameException
	{
		if ( getPropertyDefn( propName ) == null )
			throw new PropertyNameException( this, propName );
	}
	/**