vhost-v0.17.0

Added
=====

- [[#355]](https://github.com/rust-vmm/vhost/pull/355) Add socket-cloning helpers for backend request handlers.
- [[#360]](https://github.com/rust-vmm/vhost/pull/360) Validate AF_UNIX SOCK_STREAM socket file descriptors and
  add Error::InvalidSocketFd, Error::NotUnixSocket and Error::NotStreamSocket.

Changed
=======

- [[#364]](https://github.com/rust-vmm/vhost/pull/364) Updated vm-memory to 0.18.0
- [[#366]](https://github.com/rust-vmm/vhost/pull/366) Update virtio-bindings to v0.2.7

Fixed
=====

- [[#367]](https://github.com/rust-vmm/vhost/pull/367) Fix `SHMEM` protocol feature bit position (bit 21 → bit 22)
  to align with the vhost-user spec, and add missing `GPA_ADDRESSES` at bit 21.