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
/**
	 * Returns the file name of the module file.
	 * 
	 * @return the module file name. Returns null if the module has not yet been
	 *         saved to a file.
	 */
	public String getFileName( )
	{
		return fileName;
	}
	/**
	 * Sets the module file name. This method is only called by module reader,
	 * it's illegal to be called for other purpose.
	 * 
	 * @param newName
	 *            the new file name. It may contain relative/absolute path
	 *            information. But this name must include the file name with the
	 *            filename extension.
	 */
	public void setFileName( String newName )
	{
		fileName = newName;
	}
	/**
	 * Sets the UTF signature of this module file.
	 * 
	 * @param signature
	 *            the UTF signature of the module file.
	 */
	public void setUTFSignature( String signature )