Revert "Commit updated Javascript packages"

This reverts commit a88734348a.

build/javascript/node_modules/xtend/immutable.js

@@ -1,19 +0,0 @@
-module.exports = extend
-
-var hasOwnProperty = Object.prototype.hasOwnProperty;
-
-function extend() {
-    var target = {}
-
-    for (var i = 0; i < arguments.length; i++) {
-        var source = arguments[i]
-
-        for (var key in source) {
-            if (hasOwnProperty.call(source, key)) {
-                target[key] = source[key]
-            }
-        }
-    }
-
-    return target
-}