add component packaging

* move existing component.json => bower.json
* add test page for using component build

Looking at it now, I'm not sure component-izing it adds much value, except in terms of distribution, since it's designed as a singleton attached to `window` - and rightly so since it's basically a nice interface for a piece of infrastructure (localStorage/sessionStorage). You don't need more than one `store()`. But anyway this lets people `component install` it. Personally I might just use it directly through script tags.