Bump to v4.0.0.

chain.js

@@ -1,16 +1,36 @@
-module.exports = {
-  'chain': require('./chain/chain'),
-  'commit': require('./chain/commit'),
-  'concat': require('./chain/concat'),
-  'lodash': require('./chain/lodash'),
-  'plant': require('./chain/plant'),
-  'reverse': require('./chain/reverse'),
-  'run': require('./chain/run'),
-  'tap': require('./chain/tap'),
-  'thru': require('./chain/thru'),
-  'toJSON': require('./chain/toJSON'),
-  'toString': require('./chain/toString'),
-  'value': require('./chain/value'),
-  'valueOf': require('./chain/valueOf'),
-  'wrapperChain': require('./chain/wrapperChain')
-};
+var lodash = require('./wrapperLodash');
+
+/**
+ * Creates a `lodash` object that wraps `value` with explicit method chaining enabled.
+ * The result of such method chaining must be unwrapped with `_#value`.
+ *
+ * @static
+ * @memberOf _
+ * @category Seq
+ * @param {*} value The value to wrap.
+ * @returns {Object} Returns the new `lodash` wrapper instance.
+ * @example
+ *
+ * var users = [
+ *   { 'user': 'barney',  'age': 36 },
+ *   { 'user': 'fred',    'age': 40 },
+ *   { 'user': 'pebbles', 'age': 1 }
+ * ];
+ *
+ * var youngest = _
+ *   .chain(users)
+ *   .sortBy('age')
+ *   .map(function(o) {
+ *     return o.user + ' is ' + o.age;
+ *   })
+ *   .head()
+ *   .value();
+ * // => 'pebbles is 1'
+ */
+function chain(value) {
+  var result = lodash(value);
+  result.__chain__ = true;
+  return result;
+}
+
+module.exports = chain;