Bug 136279 Structure and table datatypes should be hidden.
Description: Structure and table datatype should be hidden. Steps to reproduce: In table data binding, I saw structure and table two datatypes. They are not supported now, so they should be removed.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/writer/DesignWriter.java
writeCustomColors( obj );
		
		writeDataSourceBinding( obj );
		
		writeTranslations( obj );
		writeContents( obj, IReportDesignModel.STYLE_SLOT,
				DesignSchemaConstants.STYLES_TAG );
		writeArrangedContents( obj, ReportDesign.COMPONENT_SLOT,
				DesignSchemaConstants.COMPONENTS_TAG );
		writeArrangedContents( obj, ReportDesign.PAGE_SLOT,
				DesignSchemaConstants.PAGE_SETUP_TAG );
		writeContents( obj, ReportDesign.BODY_SLOT,
				DesignSchemaConstants.BODY_TAG );
		writeContents( obj, ReportDesign.SCRATCH_PAD_SLOT,
				DesignSchemaConstants.SCRATCH_PAD_TAG );
		
		writeEmbeddedImages( obj );
		writer.endElement( );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.writer.ModuleWriter#getModule()
	 */
	protected Module getModule( )
	{
		return design;
	}
	/**