continue CSS linting...removed more IDs in selectors related to searchbox
more CSS linting...remove more IDs in selectors...clean up comments
update "js/menu.js" (see msg)

2 separate elements containing both the mobile-only menu and mobile-only search button images are dynamically-created and load onto the page one at a time: now load them simulatneously via a document fragment. the elements havw an id dynamically attached to them via jQuery: now dynamically attach both an id and a class via plain JavaScript.