Make sure to run tests both in a normal and a broken environment
Merge pull request #180 from ljharb/test_with_clean_and_polluted_object_prototype

Make sure to run tests both in a normal and a broken environment
Add links to standalone `String` polyfills
Merge pull request #181 from mathiasbynens/patch-1

Add links to standalone `String` polyfills
Add more standalone polyfills
small code syntax improvement