have the Files and Upload pages surface a 'portable_url' which uses the /static/ shorthand which is more portable across course runs
don't attempt to do URL rewriting in the import step, let the LMS/CMS runtimes do it on the fly on reference
add unit tests around asserting that /static/ links are not re-written on import
remove redudent asset_url return value when uploading files
add a test for the static url generation
alter the HTML editor so that it can do the /static/ <--> /c4x/ substitutions when toggling back and forth between the visual and advanced editors
fix cut/paste comment confusion