Remove dashboard links for unstarted courses

If a course is not started, the course image and title on the dashboard link
to the course about page. Because the LMS course about pages do not exist
(i.e. 404) with the marketing site enabled, we simply do not use a link if
the course has not started.

lms/static/sass/multicourse/_dashboard.scss

@@ -327,7 +327,7 @@
             color: $lighter-base-font-color;
           }
 
-          h3 a {
+          h3 a, h3 span {
             display: block;
             margin-bottom: 10px;
             font-family: $sans-serif;

lms/templates/dashboard.html

@@ -194,17 +194,20 @@
 
         <article class="my-course">
           <%
-          if has_access(user, course, 'load'):
             course_target = reverse('info', args=[course.id])
-          else:
-            course_target = reverse('about_course', args=[course.id])
           %>
 
 
 
-          <a href="${course_target}" class="cover">
-            <img src="${course_image_url(course)}" />
-          </a>
+          % if course.id in show_courseware_links_for:
+            <a href="${course_target}" class="cover">
+              <img src="${course_image_url(course)}" />
+            </a>
+          % else:
+            <div class="cover">
+              <img src="${course_image_url(course)}" />
+            </div>
+          % endif
 
           <section class="info">
             <hgroup>
@@ -218,7 +221,13 @@
               % endif
               </p>
               <h2 class="university">${get_course_about_section(course, 'university')}</h2>
-              <h3><a href="${course_target}">${course.number} ${course.display_name_with_default}</a></h3>
+              <h3>
+                % if course.id in show_courseware_links_for:
+                  <a href="${course_target}">${course.number} ${course.display_name_with_default}</a>
+                % else:
+                  <span>${course.number} ${course.display_name_with_default}</span>
+                % endif
+              </h3>
             </hgroup>
 
             <%