Nette 2.2beta compatible

**Tracy** replaces **Nette\Diagnostics**

Note: `Tracy\Helpers::editorLink` no more returns `Html` class, [see here](https://github.com/nette/tracy/blob/6386d3fcbe2a44ecae60c8f92645b43a1aa81821/src/Tracy/Helpers.php#L26-L58)