be sure to always pass in a course namespace - which can be just the location of the module itself since it has the same org/course pair - when rewriting links. Also, allow for an option parameter in get_module() to disable the wrapping of the module's HTML with the xmodule_display.html. This is needed for ancillary course content such as 'about', 'course info', which are now stored as xmodules, but should not be wrapped in xmodule_display.html as it breaks some styling
