Index: frontend/node_modules/commondir/index.js
===================================================================
--- frontend/node_modules/commondir/index.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
+++ frontend/node_modules/commondir/index.js	(revision 9af201e94b5a79beb92a30858fc54de4bc3b9449)
@@ -0,0 +1,29 @@
+var path = require('path');
+
+module.exports = function (basedir, relfiles) {
+    if (relfiles) {
+        var files = relfiles.map(function (r) {
+            return path.resolve(basedir, r);
+        });
+    }
+    else {
+        var files = basedir;
+    }
+    
+    var res = files.slice(1).reduce(function (ps, file) {
+        if (!file.match(/^([A-Za-z]:)?\/|\\/)) {
+            throw new Error('relative path without a basedir');
+        }
+        
+        var xs = file.split(/\/+|\\+/);
+        for (
+            var i = 0;
+            ps[i] === xs[i] && i < Math.min(ps.length, xs.length);
+            i++
+        );
+        return ps.slice(0, i);
+    }, files[0].split(/\/+|\\+/));
+    
+    // Windows correctly handles paths with forward-slashes
+    return res.length > 1 ? res.join('/') : '/'
+};