* Style the advanced search while keeping the old template unchanged (for now). Multi-selects are handled via the already included SlimSelect scripts.
* Add `role="main"` to `main`, which seems redundant, but is required by the Bootstrap theme's advanced search JS, otherwise the search group inputs are missing.
* Always display the (simple) search box in the header, even on the advanced search page.
* fix type inputs
** Remove SlimSelect from type inputs;
** these fields are cloned, which removes the required handlers. Since they only contain 10 options, they work well without a filter.
* add info box
** Display an info box above the search results with an edit link when advanced search is active.
* hide range slider