remove go-simple-db references from go-slog

- ref: https://github.com/GigaOM/legacy-pro/issues/3806
- particularly this [comment](https://github.com/GigaOM/legacy-pro/issues/3806#issuecomment-49641387)
- accompanying config: https://github.com/GigaOM/gigaom/pull/4903

I'm finding go_slog_search_window a confusing ID value and var name.  I saw it used earlier too.  You don't mean a window in the normal computer sense you mean a date window right?