Rewrite in Rust

[bakape]

• Rewrite using Rust stdlib
• Leave thread/async management to the caller. The lib only acts as persistent linker layer.
• Provide C bindings and header file
  • Pass errors as void* to allow casting between language-idiomatic error types
• Rust implementation should take any generic parameter implementing Hash as a Frontend Key
• C bindings should only allow keys fixed format. Bindings should (en-)/(de-)code keys to/from this format .

  struct RecacheBufferKey 
  {
    size_t size;
    uint8_t *data;
  };

• Write Go bindings
  • Go bindings should use zero copy unsafe casts for buffers
  • Marshal and unmarshal keys using encoding/gob
    • Reuse the encoder on the frontend
• Compile optimized binaries for all supported architectures and distribute them with the project