"Use OR" setting should be honored when using search engine query too

When user tries to find something with search engine, he expects that search engine will be smart. So when he asks "Best coffee mug", search engine will reply with "fine coffee mug", "coffee mug for $5", "awesome coffee mug". Default drupal search engine is not as smart as google, so it will not find the word "best" and render no results.

So, if site administrator decided to use OR for keywords, it should be used for search engines too.