Grady/authoring/rubric gui

Very Close (not complete front end work, and some deletion JS needs to be tweaked.  Other than that, it is ready for code review!  Going to be done tomorrow!
Throughout this method, you convert values to `str` (bytestring), which will break for non-ASCII unicode.  Since this is an entry point for data into the server, you should convert everything to unicode instead.  For our purposes, it's okay to assume UTF-8 encoding.