Bug 179674 Support time dimension in model
When define time dimension in model, the "itTime" property will be set. However this is not enough. We also need to know to what precision the time value should be evaluated, say, year, month, day, etc. Model needs to be enhanced to support such requirement.
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/writer/ModuleWriter.java
* 
	 * @see org.eclipse.birt.report.model.elements.ElementVisitor#visitScriptDataSet(org.eclipse.birt.report.model.elements.ScriptDataSet)
	 */
	public void visitScriptDataSet( ScriptDataSet obj )
	{
		writer.startElement( DesignSchemaConstants.SCRIPT_DATA_SET_TAG );
		super.visitScriptDataSet( obj );
		writeStructureList( obj, IDataSetModel.PARAMETERS_PROP );
		property( obj, IScriptDataSetModel.OPEN_METHOD );
		property( obj, IScriptDataSetModel.DESCRIBE_METHOD );
		property( obj, IScriptDataSetModel.FETCH_METHOD );
		property( obj, IScriptDataSetModel.CLOSE_METHOD );
		writer.endElement( );
	}
	/*
	 * (non-Javadoc)
	 * 
	 * @see org.eclipse.birt.report.model.design.elements.DesignVisitor#visitFreeForm(org.eclipse.birt.report.model.design.elements.Container)
	 */
	public void visitFreeForm( FreeForm obj )
	{
		writer.startElement( DesignSchemaConstants.FREE_FORM_TAG );
		super.visitFreeForm( obj );
		writeContents( obj, IFreeFormModel.REPORT_ITEMS_SLOT,
				DesignSchemaConstants.REPORT_ITEMS_TAG );
		writer.endElement( );
	}
	/*
	 * (non-Javadoc)
	 *