Support for primitives as target

This pull request adds support for using a prmitive as the target of a binding declaration (non-observed). Keep in mind that the binding can still be dynamic, for example you can still add observed properties as formatter argument which will recompute the value of the binding.

```html
<p>Formatted date: { '2014-10-08' | date user.dateFormat }</p>
```

Where `user.dateFormat` would be something like `"MMM DD, YYYY"`, then the rendered HTML would be:

```html
<p>Formatted date: Oct 08 2014</p>
```

#388