[bin] Add --shuffle option

`--shuffle` shuffles test files, making order completely random.

Author: mmalecki

bin/vows

@@ -62,6 +62,7 @@ var options = {
     watch: false,
     coverage: false,
     isolate: false,
+    shuffle: false,
     nocolor: !process.stdout.isTTY
 };
 
@@ -141,6 +142,9 @@ while (arg = argv.shift()) {
                 case 'supress-stdout':
                     options.supressStdout = true;
                     break;
+                case 'shuffle':
+                    options.shuffle = true;
+                    break;
                 case 'isolate':
                 case 'i':
                     options.isolate = true;
@@ -240,6 +244,14 @@ if (! options.watch) {
             : a.replace(fileExt, '');
     });
 
+    if (options.shuffle) {
+        var source = files.slice(0);
+        files.length = 0;
+        while (source.length) {
+            files.push(source.splice(Math.ceil(Math.random() * source.length) - 1, 1)[0]);
+        }
+    }
+
     runSuites(importSuites(files), function (results) {
         var status = results.errored ? 2 : (results.broken ? 1 : 0);