MBS-11861: improve loopParity classes for tablesorter (#2205)

This was only dealing with "even", but that meant that some
rows ended up with both "even" and "odd" classes, while some
that should be "odd" ended with nothing. This makes it all
work more like the actual loopParity function, where you either have
"odd" or "even".

root/static/scripts/statistics.js

@@ -32,12 +32,14 @@ tablesorter.addWidget({
     $('tbody tr', table).each(function (index) {
       if ((index + 1) % 2 === 0) {
         $(this).addClass('even');
+        $(this).removeClass('odd');
       } else {
+        $(this).addClass('odd');
         $(this).removeClass('even');
       }
     });
   },
-  id: 'evenRowClasses',
+  id: 'loopParity',
 });
 
 tablesorter.addParser({
@@ -61,7 +63,7 @@ $('#countries-table').tablesorter({
   },
   // order by descending number of entities, then name
   sortList: [[5, 1], [1, 0]],
-  widgets: ['indexFirstColumn', 'evenRowClasses'],
+  widgets: ['indexFirstColumn', 'loopParity'],
 });
 
 $('#languages-table').tablesorter({
@@ -73,12 +75,12 @@ $('#languages-table').tablesorter({
   },
   // order by descending number of entities, then name
   sortList: [[4, 1], [1, 0]],
-  widgets: ['indexFirstColumn', 'evenRowClasses'],
+  widgets: ['indexFirstColumn', 'loopParity'],
 });
 
 $('#scripts-table').tablesorter({
   headers: {[0]: {sorter: false}, [2]: {sorter: 'fancyNumber'}},
   // order by descending number of entities, then name
   sortList: [[2, 1], [1, 0]],
-  widgets: ['indexFirstColumn', 'evenRowClasses'],
+  widgets: ['indexFirstColumn', 'loopParity'],
 });