v5.0.0-1

• Beta release! Please let me know if there is anything wrong with this!
• Remove on-load and use a new dom ID based dom tracking system. Requires ES5 support for getters.
• Remove _load and _unload methods. You have to wrap instances of cache-component with on-load on your own now.
• Add _didUpdate hook so you can call dom methods after the component updates. Handy for updating a scroll position.