New rust bindings for CLIPS 6.4.2

[Przemysław Kamiński (XLII)]

Hi,

I plan to integrate CLIPS with my Rust project. I couldn't get "clips" bindings to compile, so had to roll my own. Instead of generated-bindings with Bindgen I decided to burn some tokens and get idiomatic bindings. 

Source code: https://github.com/exlee/clips-bindings

Documentation: https://docs.rs/clips-bindings/0.1.1+clips-6.4.2/clips_bindings/

Sharing in case someone is interested.

Best,

Przemysław Alexander Kamiński