WIP: Upload issues

This PR collects all commits related to upload issues #30 (closed), #18 (closed), and others

app/templates/upload.html

@@ -18,9 +18,11 @@
     {{ dropzone.config()}}
     </p>
     <p>
+        {% if confirmation_form is not None %}
         <form action="{{ url_for('submit') }}" method="post" enctype="multipart/form-data">
             {{ confirmation_form.hidden_tag() }}
             {{ confirmation_form.go(title="Confirm file uploads") }}
         </form>
+        {% endif %}
     </p>
 {%  endblock %}