templates: show unaivable courses with a special but do not forbid selecting them

polynum_blackboard/templates/_courses_selector.html

@@ -6,7 +6,7 @@
     {% else %}
     <option value="">---</option>
     {% for course in response.courses %}
-    <option {% if not course.available %}disabled{% endif %} value="{{ course.id }}">{{ course.name }}{% if not course.available %} (indisponible){% endif %}</option>
+    <option class="{% if not course.available %}unavailable{% endif %}" value="{{ course.id }}">{{ course.name }}{% if not course.available %} (indisponible){% endif %}</option>
     {% endfor %}
     {% endif %}
   </select>

polynum_blackboard/templates/document_copyrights.new_request.html

@@ -21,6 +21,9 @@
 .modal.large .modal-body {
   max-height: 600px;
 }
+option.unavailable {
+  color: #EEEEEE;
+}
 </style>
 <script src="{{ STATIC_URL }}/jquery/js/jquery.form.js"></script>
 {% endblock %}