-Factored out notebook-cell-order
-Thinking about how we load dependencies. We might want to do it either as part of notebook-load!, or more likely, as part of notebook-package!
-First crack at load-dependencies
-Added copious README notes
-Added a pretty-much working, single-threaded and title-conflated package system
Next up: making package evals use the extra worker thread, and untangling it from the title interface and model
-untangled repackage and rename on the front end
-untangled repackage and rename handlers on the back-end
-repackage calls are now processed asynchronously (which'll be good once we start loading deps on repackage)