Hide empty courses, click to show them

Fixes #7

controllers/total/templates/totalTableByCourse.pug

@@ -7,11 +7,20 @@ table.table.table-bordered.table-striped.table-hover
             th Total TD equivalent
     tbody
         each course in courses
-            tr
+            tr(class=course.totalTdEquivalent === 0 ? "no-courses" : "")
                 td #{course.name}
                 each type in types
                     td #{course[type]}
                 td #{course.totalTdEquivalent}
+        tr#extend
+            td
+                a(href="#") ...
+            each type in types
+                td
+                    a(href="#") ...
+            td
+                a(href="#") ...
+
         tr.table-active
             td
                 strong #{total.name}
@@ -25,3 +34,4 @@ p.
     If you think there is a mistake in this table, feel free to
     <a href="https://github.com/tforgione/adejs/issues/new">open an issue</a>
     exaplaining what are the problem so we can fix it. Thanks!
+