添加cache-loader，debug模式下不再使用template缓存，修复一些 bug

templates/partials/problem_sidebar.html

@@ -1,11 +1,15 @@
 {% if tdoc %}
   {% if tdoc.docType == 60 %}
     {% include "partials/problem_sidebar_homework.html" %}
+    {% if not owner_udoc %}
     {% set owner_udoc = udoc %}
+    {% endif %}
     {% include "partials/homework_sidebar.html" %}
   {% else %}
     {% include "partials/problem_sidebar_contest.html" %}
+    {% if not owner_udoc %}
     {% set owner_udoc = udoc %}
+    {% endif %}
     {% include "partials/contest_sidebar.html" %}
   {% endif %}
 {% else %}