result-apply-args

Allow arguments to be passed to object method in `_.result()` call.

Since the `_.result()` function is a handy way of conditionally calling a method that may not exist, it should support passing arguments through to the method that is being invoked.

Example:
```JavaScript
// Underscore hotness:
var answer = _.result(obj, 'z', 'foo');

// Rough equivalent in pure JS:
var answer;
if (obj && obj.z) {
  answer = obj.z('foo');
}
```