Some IE8 Compatibility

While working on adding IE8 compatibility for component/dom, I came across this. (enumerable doesn't have a browser-based test runner atm, but I can add that if we want to ensure it's still compatible)

I've added a new dependency, settling on this particular "isArray" implementation because the same library exists both as a component and an npm module. (otherwise I'd have to do `try...catch` or something around the `require`... yuck)