Closes #764: always search stopwords lowercased

sphinx/themes/basic/static/searchtools.js_t

@@ -150,7 +150,7 @@ var Search = {
           objectterms.push(tmp[i].toLowerCase());
       }
 
-      if ($u.indexOf(stopwords, tmp[i]) != -1 || tmp[i].match(/^\d+$/) ||
+      if ($u.indexOf(stopwords, tmp[i].toLowerCase()) != -1 || tmp[i].match(/^\d+$/) ||
           tmp[i] === "") {
         // skip this "word"
         continue;