Returning non-promise value via config prop

New config property ```promised -> true|false -> default true```

If ```false``` then resolve promise before returning on ```open()``` and ```close() ```

Implementation example:
```
var overlay = $('.test').overlayAsPromised({
    promised: false
}, function() {
    return "test";
});

var result = overlay.open();

console.log(result);

// output --> "test"
```