Fixes skipping of parent classes

Should fix this issue: #529

This will always perform the check for $suiteClassName inside loaded classes
> appending is done without array_merge to prevent creating a new array copy

mmm, this is a user-space re-implementation of `array_merge()`.

I still think we can avoid all of the ordering issues by simply merging arrays in the most effective order:
```php
$this->foundClasses = array_merge($newClasses, $this->foundClasses);
```
→ Immediately new classes are processed first.  Only if there's no match, previously discovered classes are processed in approx. LILO order.