Polish language for XenForo 2 2.3.6

I have spent a lot of time to bring XenForo this language pack and now I am pleased to inform you, that the most of translation is done.

This translation contains:

• everything that users can see, additional pages (terms and rules, privacy policy), bb-code editor, time and dates, messages, reminders, smiles, system errors etc.
• moderator tools,
• most of administration control panel and its tools,
• no machine translation! This language pack has been tested in many scenarios,
• no visible branding.