Closes #60. select: save option.value to model and not entire option

The way data is stored in the result object is different for select and radio. I think it is a bug. If it was designed on purpose, could you explain why?

Here is the plunker: http://plnkr.co/edit/dUiO4aWXQoZlyuE6L5iy

selecting a item using the select will store the complete object in the result
result.triedEmberSelect: {
"name": "Yes, and I love it!",
"value": "yesyes"
}

selecting an item using the radio will store only the value:
result.triedEmberRadio: "yesyes"

Thanks in advance, great module!