[bug 1100394] Implement simple_query_search in Advanced Search.

This was pretty easy. I still need to decide where the documentation should go. I kind of think it should be a KB article linked right from an (?)icon to the right of the search box.

Anyway, r?.

oh I see what you are saying. But I think we will always hit the case below. Hmmm. I included this just for completeness.