Bug 200471 Add "need not sort for grouping" option in report item
Currently when Data engine proceeds groups, it always sorts the result set according to given group key.However that should not be necessary when the raw data is already sorted. So we'd like to add new options so that user can indicate whether should we sort the data before grouping. In model, we should allow user to set a "need not do sort for grouping" option to all the report element that can be grouped(table, list,etc.)
model/org.eclipse.birt.report.model/src/org/eclipse/birt/report/model/writer/ModuleWriter.java
list = (ArrayList) obj.getLocalProperty( getModule( ),
				IStyleModel.MAP_RULES_PROP );
		if ( list != null && list.size( ) > 0 )
		{
			writer.startElement( DesignSchemaConstants.LIST_PROPERTY_TAG );
			writer.attribute( DesignSchemaConstants.NAME_ATTRIB,
					IStyleModel.MAP_RULES_PROP );
			for ( int i = 0; i < list.size( ); i++ )
			{
				MapRule rule = (MapRule) list.get( i );
				writer.startElement( DesignSchemaConstants.STRUCTURE_TAG );
				property( rule, StyleRule.IS_DESIGN_TIME_MEMBER );
				property( rule, StyleRule.TEST_EXPR_MEMBER );
				property( rule, StyleRule.OPERATOR_MEMBER );
				property( rule, StyleRule.VALUE1_MEMBER );
				property( rule, StyleRule.VALUE2_MEMBER );
				resourceKey( rule, MapRule.DISPLAY_ID_MEMBER,
						MapRule.DISPLAY_MEMBER );
				writer.endElement( );
			}
			writer.endElement( );
		}
	}
	/**
	 * Writes the contents of the container information. The contents are
	 * enclosed in an optional list tag.
	 * 
	 * @param containerInfor
	 *            the container infor