New snapd 2.23 release

[Michael Vogt]

Hi,

The snappy team is happy to announce the new snapd 2.23 release!

The new release is available in the "core" (and "ubuntu-core") snap on
the "candidate" channel and also in the Ubuntu 14.04, 16.04, 16.10
"proposed" pockets and in 17.04.

To install this new release you need to run the following command:

  $ sudo snap refresh --beta core

On the classic distribution you can help testing by enabling -proposed
and then installing snapd [1].

Some highlights:
- add support for seeding on classic
- all interfaces support send*,recv* syscalls now
- xdelta3 is used from the core snap
- `snap info` shows contact information
- support for galliumos, serena
- shell completion for connect
- move auto-refresh inside snapd
- create "current" symlink in user-data dir
- UI improvements
- many bugfixes
- New interfaces:
  - thumbnailer, classic-support, network-setup-control,
    linux-frame-buffer, unity8
- Interface improvements:
  - screen-inhibit-control, network-control, firewall-control, unity7,
    default, serial, core-support, hardware-observe,
    kernel-module-control, udisks2

Please let us know if you experience any issues or if you have
suggestions!

Enjoy the new release,
 Michael (on behalf of the snappy team)

[1] https://wiki.ubuntu.com/Testing/EnableProposed