This removes the `rebind_noauth_module_to_user` argument from the ModuleSystem constructor and moves it to a separate service called "rebinder" in the class `RebindModuleService`. This is used in the LTI module to bind calls received by its noauth endpoint to bind the module the real_user.
common ------ This directory contains common code shared between LMS and CMS, such as Mako templates, CSS, and Coffescript.