Out of sync (from Rust v0.2.6 to maybe v0.3?)

https://github.com/CoLearn-Dev/colink-sdk-rust-dev/pulls?q=is%3Apr+is%3Aclosed after its `#35`

Major changes:

- macOS support
- MQ alternative
- Call forwarding
- set/get_var renaming to send/recv
- Storage macro support (Redis, Append, Redis+Append) - for this one maybe we can do something smarter 😄 