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 a list containing warnings during parsing the module file.
	 * 
	 * @return a list containing parsing warnings. Each element in the list is
	 *         <code>ErrorDetail</code>.
	 * 
	 * @see ErrorDetail
	 */
	public List getWarningList( )
	{
		List allErrors = getAllErrors( );
		return ErrorDetail.getSemanticErrors( allErrors,
				DesignFileException.DESIGN_EXCEPTION_SEMANTIC_WARNING );
	}
	/**
	 * Performs a semantic check of this element, and all its contained
	 * elements. Records errors in the module context.
	 * <p>
	 * Checks the contents of this element.
	 * 
	 * @param module
	 *            the module information needed for the check, and records any
	 *            errors
	 */
	public final void semanticCheck( Module module )
	{
		allExceptions = validateWithContents( module );
		
		if ( module instanceof ReportDesign )
		{
			ContainerSlot slot = module