mod_client_management: Include client software version number in listing Should you ever wish to revoke a client by version number, e.g. for security reasons affecting certain versions, then it would be good to at the very least see which version is used. Also includes the OAuth2 software ID, an optional unique identifier that should be the same for all installations of a particular software.

Over the years, some servers stop working for various reasons, and leave
behind broken roster subscriptions that trigger failing s2s connections.
This module allows cleaning up such cases by unsubscribing local users
from their contacts on those servers. Also works for typos and the like.
Use with care.

```lua
Component "gmail.com" "unsubscriber"
```