Expose file-descriptor and read-one-request/write-one-reply functions for use in event loops about fuse-rs HOT 2 OPEN

let FUSE: Token = Token(0);
let poll = Poll::new()?;
let fuse_handle = fuse::mount_evented(fs, mountpoint, &[])?;
// Start listening for incoming connections
poll.register(&fuse_handle, FUSE, Ready::readable(),
              PollOpt::edge())?;
// Other potential registers here

// Create storage for events
let mut events = Events::with_capacity(1024);
loop {
    poll.poll(&mut events, None)?;

    for event in events.iter() {
        match event.token() {
            FUSE => {
                fuse_handle.handle_one_request();
            }
            // Handle other registers
            _ => unreachable!(),
        }
    }
}