Show layer notes records as alerts on layer detail

These can be used to show important notes (e.g. "This layer is
deprecated, use layer xyz instead.") as eye-catching alerts at the top
of the detail page.

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>

TODO

@@ -18,7 +18,6 @@ TODO:
 * Recipe info page
 * Captcha for layer submission interface?
 * Touch up publishing interface
-* Show layer notes records
 
 Later:
 * Show count of layers to be reviewed next to review button

layerindex/detail.html

@@ -35,6 +35,14 @@
         </div> <!-- end of container-fluid -->
 
         <div class="container-fluid">
+            <div class="row-fluid">
+                {% for note in layeritem.layernote_set.all %}
+                    <div class="alert">
+                        {{ note.text }}
+                    </div>
+                {% endfor %}
+            </div>
+
             <div class="row-fluid">
                 <div class="description span7">
                     <p>