Fix URLs for static resources

lms/templates/courseware/xqa_interface.html

-<script type="text/javascript" src="/static/js/vendor/jquery.leanModal.min.js"></script>
+<%namespace name='static' file='/static_content.html'/>
+
+<script type="text/javascript" src="${static.url('js/vendor/jquery.leanModal.min.js')}"></script>
 <script type="text/javascript">
 
 function setup_debug(element_id, edit_link, staff_context){

lms/templates/open_ended_problems/combined_notifications.html

@@ -36,7 +36,7 @@
                     <a href="${notification['url']}" class="notification-link">
                         <div class="notification-title">${notification['name']}</div>
                         %if notification['alert']:
-                        <p class="alert-message"><img src="/static/images/grading_notification.png" /> ${notification['alert_message']}</p>
+                        <p class="alert-message"><img src="${static.url('images/grading_notification.png')}" /> ${notification['alert_message']}</p>
                         %endif
                     <div class="notification-description">
                         <p>${notification['description']}</p>

lms/templates/static_pdfbook.html

@@ -10,10 +10,10 @@
 <%static:css group='style-course-vendor'/>
 <%static:css group='style-course'/>
 <%static:js group='courseware'/>
-<link rel="stylesheet" href="/static/css/pdfviewer.css"/>
-<script type="text/javascript" src="/static/js/vendor/pdfjs/pdf.js"></script>
-<script type="text/javascript" src="/static/js/vendor/pdfjs/compatibility.js"></script>
-<script type="text/javascript" src="/static/js/pdfviewer.js"></script>
+<link rel="stylesheet" href="${static.url('css/pdfviewer.css')}"/>
+<script type="text/javascript" src="${static.url('js/vendor/pdfjs/pdf.js')}"></script>
+<script type="text/javascript" src="${static.url('js/vendor/pdfjs/compatibility.js')}"></script>
+<script type="text/javascript" src="${static.url('js/pdfviewer.js')}"></script>
 </%block>
 
 <%block name="js_extra">