It is useful to know when the stylesheet has been loaded in order to prevent displaying unstyled content.
CalendarView and the dashboard_graph widget (JournalDashboardGraph) use loadCSS through cssLibs / loadLibs so the tests now have to use createAsyncView instead of createView.
Before this commit, only the routes which began by '/web/image' were
mocked (simply ignored). This forgot the case were it is a full URL
(http://www.test.com/web/image). Now, also mock the static images
routes (for .png and .jpg).