Fix for object method calls no longer showing

The earlier closures fix actually caused a regression. Any callbacks given in array form, such as the below examples, were no longer showing in the filters list. As this is one of the most used (and advocated) forms in plugins, this effectively rendered the plugin nearly useless. This pull request fixes that.

```php
add_filter( 'filter_name', array( $this, 'method_name' ) );
add_filter( 'filter_name', array( __CLASS__, 'method_name' ) );
```

The pull request is release ready, i.e. changelog has been updated, the version numbers have been upped and I've tested my changes in WP 3.6, 3.7 and 3.8.

Adiitionally I've added two test files with example `add_filter()` calls which should all work & be displayed by the plugin. These do not have to be included in the actual plugin release, but are useful for testing of future changes to the filter list display function.