Bug 197228 Need updaet createdBy info when serialize the module
When open module, designer will pass the property map which contains the createdBy info. this info should be retained by moduleHandle and then be updated and written when doing serialization. Note if this info is null, model should not update it during serialization. This could happen for api users or third-party designer. For BIRT designer, it will guarantee this value always not null.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/core/Module.java
* relative/absolute file directory or a network path such as HTTP, FTP,
	 * etc.
	 */
	protected URL systemId = null;
	/**
	 * The UTF signature.
	 */
	protected String signature = null;
	/**
	 * The default units for the design.
	 */
	protected String units = null;
	/**
	 * All libraries which are included in this module.
	 */
	private List libraries = null;
	/**
	 * The attribute listener list to handle the file name changed events.
	 */
	private List attributeListeners = null;
	/**
	 * Dispose listener list to handle the design disposal events.
	 */
	private List disposeListeners = null;
	/**
	 * Resource change listener list to handle the resource change events.
	 */
	private List resourceChangeListeners = null;
	/**
	 * The theme for the module.