migration fixes and notification

fixes #1416  (includes it); and handles changing colorCommentScore non-default values to the appropriate enum value; and shows notification  if colorCommentScore option was updated from false to none on upgrade (to remedy's 4.5.0.1 failure to do so)

waits until body is ready to show notifications
yeah, this is just my "oh shit oh shit something borked" fallback check.. probably really only applies in development but it seemed worth keeping because we keep seeing other weird unexpected bugs once code gets out in the field