More changes to uploads:

- Have got upload images appearing in the post list
- Allowed for deleting uploads
- Allowed for seeing the upload progress
- Fixed the setting of upload properties like the MIME type
- Removed the stripe exif logic with just re-encoding PNGs and JPEGs by loading them and saving them

views/_common/nav.html

@@ -10,6 +10,9 @@
         <li class="nav-item">
           <a class="nav-link active" aria-current="page" href="/sites/{{.site.ID}}/posts">Posts</a>
         </li>
+        <li class="nav-item">
+          <a class="nav-link active" aria-current="page" href="/sites/{{.site.ID}}/uploads">Uploads</a>
+        </li>
       </ul>
       <form class="d-flex align-items-center" role="search">
         <!--