Add a first_time_user attribute to CourseModule so that we can check for that…

Add a first_time_user attribute to CourseModule so that we can check for that explicitly, rather than looking for an implicitly created StudentModule

common/lib/xmodule/xmodule/course_module.py

@@ -89,8 +89,18 @@ class TextbookList(ModelType):
         return json_data
 
 
+class CourseModule(SequenceModule):
+    first_time_user = Boolean(help="Whether this is the first time the user has visited this course", scope=Scope.student_state, default=True)
+
+    def __init__(self, *args, **kwargs):
+        super(CourseModule, self).__init__(*args, **kwargs)
+
+        if self.first_time_user:
+            self.first_time_user = False
+
+
 class CourseDescriptor(SequenceDescriptor):
-    module_class = SequenceModule
+    module_class = CourseModule
 
     textbooks = TextbookList(help="List of pairs of (title, url) for textbooks used in this course", default=[], scope=Scope.content)
     wiki_slug = String(help="Slug that points to the wiki for this course", scope=Scope.content)