First support for md extensions; Package all needed dependencies in the repo

Source/node_modules/core-js/modules/es7.math.degrees.js

@@ -0,0 +1,9 @@
+// https://rwaldron.github.io/proposal-math-extensions/
+var $export = require('./_export');
+var RAD_PER_DEG = 180 / Math.PI;
+
+$export($export.S, 'Math', {
+  degrees: function degrees(radians) {
+    return radians * RAD_PER_DEG;
+  }
+});