Change parseFloat() to Number()

Number() is a bit less forgiving than parseFloat() and is more likely to generate NaN rather than some random number.  An audit of each case shows nowhere that parseFloat()’s features are needed.

generators/javascript/lists.js

@@ -354,7 +354,7 @@ Blockly.JavaScript['lists_sort'] = function(block) {
           '(type, direction) {',
        '  var compareFuncs = {',
        '    "NUMERIC": function(a, b) {',
-       '        return parseFloat(a) - parseFloat(b); },',
+       '        return Number(a) - Number(b); },',
        '    "TEXT": function(a, b) {',
        '        return a.toString() > b.toString() ? 1 : -1; },',
        '    "IGNORE_CASE": function(a, b) {',