Internal/External Studio file URLs

- Changed link URL of file name to use public/LMS url
- Added toggle link to display all public URLs for instructor convenience

cms/templates/js/asset-library.underscore

@@ -16,7 +16,8 @@
             <th class="thumb-col"><%= gettext("Preview") %></th>
             <th class="name-col sortable-column"><span class="column-sort-link" id="js-asset-name-col"><%= gettext("Name") %></span></th>
             <th class="date-col sortable-column"><span class="column-sort-link" id="js-asset-date-col"><%= gettext("Date Added") %></span></th>
-            <th class="embed-col"><%= gettext("URL") %></th>
+            <th class="embed-col"><%= gettext("Embed URL") %></th>
+            <th class="embed-col"><%= gettext("External URL") %></th>
             <th class="actions-col"><span class="sr"><%= gettext("Actions") %></span></th>
         </tr>
         </thead>

cms/templates/js/asset.underscore

@@ -16,6 +16,9 @@
 <td class="embed-col">
     <input type="text" class="embeddable-xml-input" value="<%= portable_url %>" readonly>
 </td>
+<td class="embed-col">
+    <input type="text" class="embeddable-xml-input" value="<%= external_url %>" readonly>
+</td>
 <td class="actions-col">
     <ul class="actions-list">
         <li class="action-item action-delete">
@@ -27,4 +30,4 @@
             <div class="action-button"><i class="icon-lock"></i><i class="icon-unlock-alt"></i></div>
         </li>
     </ul>
-</td>
+</td>