Pure rust ostree FUSE implementation

["Will Manley" <will williammanley net>]

I've written a FUSE implementation which is backed by an ostree bare-user repo:

https://github.com/wmanley/ostree-oxide

It's written in pure rust and doesn't link to libostree or glib.  I'm using a Rust GVariant implementation 
that I wrote for this purpose:

https://docs.rs/gvariant/0.3.0/gvariant/

It's just a proof of concept, but may evolve to something useful for ostree-based build systems in the 
future. Alternatively the ostree-repo crate may evolve to a more complete ostree library. I don't have any 
concrete plans to do either right now though, but I may tinker with it from time to time.  I mostly wrote 
this for my own curiosity.

Thanks

Will