Port to .NET Core and low-level bindings

[ststeiger]

It works kind-of fine, but for making it work efficiently when reading/writing into a RDBMS-dababase and/or mongoDB, it should bind the low-level API where I could use the INODE as uid, instead of concatenated paths which need to be computed at search-time, or stored which violates the non-redundancy rule.

More like jLowFuse
https://github.com/irq0/jlowfuse
or
https://github.com/vgough/go-fuse-c

With paths, it is kinda slow and hard to maintain ...

Also, waiting for .NET Core version.