be more forgiving about the iframe url

If anything after mktg/ does not parse as a course-id return "coming soon"
This will prevent 404 errors when urls are incorrect on the marketing
site.

lms/djangoapps/courseware/views.py

@@ -537,7 +537,7 @@ def mktg_course_about(request, course_id):
 
     try:
         course = get_course_with_access(request.user, course_id, 'see_exists')
-    except Http404 as e:
+    except (ValueError, Http404) as e:
         # if a course does not exist yet, display a coming
         # soon button
         return render_to_response('courseware/mktg_coming_soon.html',

lms/urls.py

@@ -185,9 +185,13 @@ if settings.COURSEWARE_ENABLED:
         #About the course
         url(r'^courses/(?P<course_id>[^/]+/[^/]+/[^/]+)/about$',
             'courseware.views.course_about', name="about_course"),
-        #View for mktg site
+        #View for mktg site (kept for backwards compatibility TODO - remove before merge to master)
         url(r'^courses/(?P<course_id>[^/]+/[^/]+/[^/]+)/mktg-about$',
             'courseware.views.mktg_course_about', name="mktg_about_course"),
+        #View for mktg site
+        url(r'^mktg/(?P<course_id>.*)$',
+            'courseware.views.mktg_course_about', name="mktg_about_course"),
+
 
 
         #Inside the course