Dutch translation for XenForo 2.2 + add-ons 2.2.15

• Updated phrases for XF 2.1.1
• Refined much more phrases making the translation more consistent

This is a major update:

• 1000+ outdated phrases have been reviewed, refined and/or translated. We now have 0 outdated phrases for XF 2.1! However we are not finished yet. There are enough phrases left to be translated.
• Removed lots of those annoying capitals coming from the 1.5 release, like "Post New Thread".
• Updated loads of phrases to be more consistent.

If you have any suggestions, corrections or improvements, please let me know. You can post a request in this topic or PM me if you like