-Added explanatory comment on kill-notebook event. Should choose better function name for `relevant-event?` to prevent the need entirely
-Added :sb-introspect as a conditional package dependency so that raw SBCL could quit bitching
-Mostly working notebook repackaging system (still need to put together the front end and handle a few edge-cases in terms of newly importing symbols that are already in the package. Maybe a few others; we'll see)
-Changed the rename interface so that it carries package information
-Added the repackage back-end handler
Next up: finish up the front-end interface for repackaging