Added the underscore node_module.

node_modules/underscore/amd/isEmpty.js

@@ -0,0 +1,18 @@
+define(['./_getLength', './isArray', './isString', './isArguments', './keys'], function (_getLength, isArray, isString, isArguments, keys) {
+
+  // Is a given array, string, or object empty?
+  // An "empty" object has no enumerable own-properties.
+  function isEmpty(obj) {
+    if (obj == null) return true;
+    // Skip the more expensive `toString`-based type checks if `obj` has no
+    // `.length`.
+    var length = _getLength(obj);
+    if (typeof length == 'number' && (
+      isArray(obj) || isString(obj) || isArguments(obj)
+    )) return length === 0;
+    return _getLength(keys(obj)) === 0;
+  }
+
+  return isEmpty;
+
+});