Improve suggestions, step 2

Every change here is given to trade-off suggestions performance (p) and
relevancy (r).

- just check bookmarks for relevance if no history entries found (p)

- remove bookmarks item duplicates from history (r)
- just do it is user typed more than 1 char (p)

- order history entries just if user typed more than 1 char (p)
- (reverse) order by visit count (most visited first) (r)