Update framework.php #1487

#1487 
How to get a default value:

global $sampleReduxFramework
$sampleReduxFramework->ReduxFramework->get_default_value('option_id', 'optional_array_key');
I think I'd change this to

```
if (empty($this->options_defaults)) {
    $this->options_defaults = $this->_default_values();
}

$defaults = $this->options_defaults;

```

And, why `$value = NULL;` since it's going to be set one way or another via if/end.  Also, the formatting needs to be up to spec.  :)