v0.3.0

While this release introduces a breaking change, most of the API has been pretty
stable for a long time. Consider this a 1.0.0 release candidate.

• Breaking changes

  • Persistence functions raise an exception rather than return :noop when
    persistence has been disabled.
  • Error tuples all return Exception structs rather than atoms. This cleans up
    some error handling inconsistencies, but will require changes to any code
    that tries to interpret the error atoms.

• New features

  • Add raising versions (e.g., bang versions) of persistence functions