This commit also includes a policy helper
`policy_extras.listener_domains` to make it convenient to define
listener domains in toml and/or json files.
To facilitate this, the DomainMap rust structure has been exposed
to lua code via the new `kumo.domain_map.new` function.
The assets/policy-extras dir is now deployed to
`/opt/kumomta/share/policy-extras` and added to the require path,
so you can do:
```lua
local shaping = require 'policy-extras.shaping'
```
to pull it into your policy.
Wez Furlong
Tom Mairs