Deploy: post-check for overridden config in destination environment?

[dalin-]

Common scenario:

1. Make some config changes locally
2. Push it up to a multidev
3. Deploy
4. The live site shows some overridden config, but it's all benign (like different sorting, or null replaced with an empty array).

After the deploy step is complete, we could check for overridden config, and if found prompt. Either:

• If on live/test prompt to run pantheon-multidev-create (which will automatically deal with overridden config)
• If on dev/multidev run drupal_config_export() with $checkforoverrides=1