Add basic crypto support (alpha)
Merge branch 'crypto'
Housekeeping
README tweak (crypto)
Fix crypto encryption ba-concat order
Crypto: simplify design, add auto salting

Have decided to simplify the API even further and bring configuration down to
essentially one decision: do you want auto salting, or key caching?
Merge branch 'dev'
README: Add crypto docs
Housekeeping
Add helpful thaw exceptions
Housekeeping
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
Update README for new API
Add lein :bench profile & alias
Optimize collection creation (much faster)