clarify and internationalize the search spell correction message.

common/static/coffee/src/discussion/views/discussion_thread_list_view.coffee

@@ -460,7 +460,12 @@ if Backbone?
             @collection.current_page = response.page
             @collection.pages = response.num_pages
             if !_.isNull response.corrected_text
-              @addSearchAlert('Showing results for "' + response.corrected_text + '"');
+              message = interpolate(
+                _.escape(gettext('No results found for %(original_query)s. Showing results for %(suggested_query)s.')),
+                {"original_query": "<em>" + _.escape(text) + "</em>", "suggested_query": "<em>" + response.corrected_text + "</em>"},
+                true
+              )
+              @addSearchAlert(message)
             # TODO: Perhaps reload user info so that votes can be updated.
             # In the future we might not load all of a user's votes at once
             # so this would probably be necessary anyway

lms/static/sass/discussion/_discussion-developer.scss

@@ -45,8 +45,12 @@ body.discussion {
       // alert copy
       .message {
         @include font-size(12);
-        @extend %t-weight5;
         color: $white;
+
+        em {
+          @extend %t-weight5;
+          font-style: italic;
+        }
       }
 
       // links to jump to users/content in alerts

lms/templates/discussion/_underscore_templates.html

@@ -311,7 +311,7 @@
 <script aria-hidden="true" type="text/template" id="search-alert-template">
     <div class="search-alert" id="search-alert-${'<%- cid %>'}">
         <div class="search-alert-content">
-          <p class="message">${'<%- message %>'}</p>
+          <p class="message">${'<%= message %>'}</p>
         </div>
 
         <div class="search-alert-controls">