(bug 38670) Provide a no results found view

Provide a view showing:
- A feedback message where the current search term is displayed.
- Suggested options: based on likely languages and languages with one
additional level of editing distance than the used in the search algorithm.
- Instructions for search and browse including links to all the sub-regions
available.

* Introduced success, noresults callbacks for language and region filters
* Region filter can be a link for a region alone.

Change-Id: I713b62911bb32e1b1427320ced767b144180c5c4

examples/resources/demo.css

@@ -17,4 +17,4 @@ span.uls-trigger {
 span.uls-trigger a {
 	color: #FFFFFF;
 	font-weight: bold;
-}
+}