cl-prevalence / TODO

* introduce global state that doesn't get reset

* move txn-state to serialize-xxx, local-state

* possibly make local-state a function parameter instead
  of a dynamic var

* fix SEXP serializer

* fix managed prevalence

* add tests for correct object ref (de-)serialization

* test suite -> fiveam

* s-serialization should probably become a separate library

* progress display

* continuable errors on deser

* printer for systems should display directory, possibly other useful info