added Nette\Bridges

All DI extensions, Tracy panels and Latte macros moved to Nette\Briges.

In fact, I am not sure this directory structure is OK. Should it be `Nette\Bridges\DI\NetteExtension.php` `Nette\Bridges\DI\Nette\Extension.php` or `Nette\Bridges\Nette\DI\Extension.php`?