Update tests, migrate to Expectations lib
Drop Clojure 1.3 support
Mark `freeze-to-stream!` and `thaw-from-stream!` as private
Housekeeping prep for new API
Swap `repeatedly` -> `utils/repeatedly*` (faster)
Further prep for new API, mark `freeze-to-bytes` and `thaw-from-bytes` as deprecated
Optimize collection creation (much faster)