Automatically bind store methods

Bind store methods for consistent behavior with react components.

@spoike react requires an es5 shim if you want to support older browsers so I'm not sure there's a need to include a `Function.prototype.bind` polyfill:

http://facebook.github.io/react/docs/working-with-the-browser.html#browser-support-and-polyfills
https://github.com/facebook/react/blob/2bdad81955e160a5b11110b40c7222a1113cc1fb/src/browser/ui/React.js#L150