fix "Steps in Catalog.xml aren't ordered by StepsType/Difficulty"

stepmania/src/CatalogXml.cpp

@@ -53,13 +53,13 @@ void SaveCatalogXml()
 		pSongNode->AppendChild( "MainTitle", pSong->GetDisplayMainTitle() );
 		pSongNode->AppendChild( "SubTitle", pSong->GetDisplaySubTitle() );
 
-		vector<Steps*> vpSteps = pSong->GetAllSteps();
-		for( unsigned j=0; j<vpSteps.size(); j++ )
+		FOREACH_StepsType( st )
 		{
-			Steps* pSteps = vpSteps[j];
-		
-			if( pSteps->IsAutogen() )
-				continue;
+			FOREACH_Difficulty( dc )
+			{
+				Steps* pSteps = pSong->GetStepsByDifficulty( st, dc, false );	// no autogen
+				if( pSteps == NULL )
+					continue;	// skip
 
 				StepsID stepsID;
 				stepsID.FromSteps( pSteps );
@@ -71,6 +71,7 @@ void SaveCatalogXml()
 				pStepsIDNode->AppendChild( pSteps->GetRadarValues().CreateNode() );
 			}
 		}
+	}
 
 
 	vector<Course*> vpCourses;