Regarding "List of Keywords" | "Keyword" | "Search Engine" | "Bing Images" the link to Bing Image Search is wrong.
Current version is http://www.bing.com/images/search/search?q=tuttlingen+landschaft
But the right version is http://www.bing.com/images/search?q=tuttlingen+landschaft
So one "search/" is too much!
the problem is in [https://github.com/piwik/piwik/blob/master/plugins/Referers/functions.php#L98]