handling list of object as datasets

I've problem when datasets are objects and using angularJS 1.2.0 (it works fine with angular 1.0.8).

as you can see here http://plnkr.co/x8YSof, after selecting the item, it shows [object Object].

So, i made a bit modification and refactoring. http://plnkr.co/vDLQ5x

Please accept the pull request if you think it's good.

Thanks