split-gpg2 should source a configuration directory

[ben-grande]

How to file a helpful issue

The problem you're addressing (if any)

Configuration directory is very good for drop-in configurations. Currently, if I want to deliver a configuration policy, it will overwrite user configuration in ~/.config/qubes-split-gpg2/qubes-split-gpg2.conf.

The solution you'd like

Include a configuration directory such as ~/.config/qubes/split-gpg2/conf.d/*.conf. This way, I can separate configuration from different clients:

qubes-split-gpg2.conf:

[DEFAULT]
autoaccept = 86400

conf.d/work.conf:

[client:work-code]
autoaccept = 86400

conf.d/builder.conf:

[client:qubes-builder]
autoaccept = 86400

[client:mirage-builder]
autoaccept = 86400

If configuration directories are sourced, I can add and remove configuration without messing with the user settings or using a toml parser when deploying with SaltStack.

The value to a user, and who that user might be

User's can use a single split-gpg2 server and having configurations deployed in an idempotent manner. Packagers can provide split-gpg2 configurations without overwriting user configuration when they deploy qubes for users such as qubes-builder or qubes-secpack qube with the necessary keys the split-gpg2 server to verify the repository.

[ben-grande]

PR submitted.

User can override any drop-in configuration file with ~/.config/qubes-split-gpg2/qubes-split-gpg2.conf.

The drop-in configuration files can override the [DEFAULTS] section.