v0.52.3178

• Fixed: .UseFilesEventStore now uses a thread safe singleton instance for
  file system persistence, making it suitable for use in multi-threaded unit
  tests. Please don't use the files event store in production scenarios
• New: Support for unicode characters in type names. This simplifies using an
  ubiquitous language
  in non-english domains
• Fixed: Include hyphen in prefix validation for identity values. This fixes a bug
  where invalid identities could be created (e.g. ThingyId.With("thingyINVALID-a41e..."))