Expose lodash in the amd fork of the UMD in case it's being loaded with a shim config. [closes #400]

dist/lodash.underscore.js

@@ -4898,6 +4898,11 @@
 
   // some AMD build optimizers like r.js check for condition patterns like the following:
   if (typeof define == 'function' && typeof define.amd == 'object' && define.amd) {
+    // Expose Lo-Dash to the global object even when an AMD loader is present in
+    // case Lo-Dash is loaded with a RequireJS shim config.
+    // See http://requirejs.org/docs/api.html#config-shim
+    root._ = lodash;
+
     // define as an anonymous module so, through path mapping, it can be
     // referenced as the "underscore" module
     define(function() {