Make tags section more consistent

The tags section currently has a "button" which looks completely
different to all other buttons on the page, and also is the only
button which remains visible when logged out. The heading is also
slightly different to the other headings on the story detail view.

This commit fixes these inconsistencies to bring the tags section
in line with the rest of the story detail view.

Change-Id: Iceb368674849a08cc6e4456b8f7cfc283fc24a4f

src/app/stories/template/detail.html

@@ -349,9 +349,9 @@
 
 <!-- Template for the tags list and controls -->
 <script type="text/ng-template" id="/inline/tags.html">
-    <strong>Tags</strong>
+    <h3>Tags</h3>
 
-    <ul class="list-inline">
+    <ul class="list-inline" ng-if="story.tags.length > 0">
         <li ng-repeat="tag in story.tags">
             <h4>
                 <span class="label label-warning">
@@ -361,32 +361,26 @@
                 </span>
             </h4>
         </li>
-        </ul>
-        <br>
-        <span class="input-group" ng-show="showAddTag">
-           <input type="text" class="form-control" ng-model="newTag.name"
-             typeahead="tag as tag.name for tag in searchTags($viewValue)"
-             typeahead-on-select="updateViewValue($model.name);"/>
+    </ul>
+    <p class="text-muted" ng-if="story.tags.length == 0 && !isLoggedIn">
+        <em>This story has no tags yet.</em>
+    </p>
+    <span class="input-group" ng-show="showAddTag">
+       <input type="text" class="form-control" ng-model="newTag.name"
+         typeahead="tag as tag.name for tag in searchTags($viewValue)"
+         typeahead-on-select="updateViewValue($model.name);"/>
 
-            <span class="input-group-btn">
-                <button class="btn btn-primary" type="button"
-                        ng-click="addTag(newTag.name)">Add</button>
-                <button class="btn btn-default" type="button"
-                        ng-click="toggleAddTag()">Cancel</button>
-            </span>
+        <span class="input-group-btn">
+            <button class="btn btn-primary" type="button"
+                    ng-click="addTag(newTag.name)">Add</button>
+            <button class="btn btn-default" type="button"
+                    ng-click="toggleAddTag()">Cancel</button>
         </span>
-        <h4>
-            <span class="label label-default" ng-click="toggleAddTag()"
-                  ng-show="!showAddTag && isLoggedIn">
-                Add
-                <i class="fa fa-plus"></i>
-            </span>
-            <span class="label label-default" ng-click="showLoginRequiredModal()"
-                  ng-show="!isLoggedIn">
-                Add
-                <i class="fa fa-plus"></i>
-            </span>
-        </h4>
+    </span>
+    <button class="btn btn-default" ng-click="toggleAddTag()"
+            ng-show="!showAddTag && isLoggedIn">
+        <i class="fa fa-plus-circle"></i>&nbsp;Add Tag
+    </button>
 </script>
 
 <!-- Template for the task list -->