While I do not agree with _every_ style change, this will force Dokku to have consistent formatting across all shell scripts, which is arguably a Good Thing™.
The command used to reprocess everything is:
```shell
shfmt -l -bn -ci -i 2 -w .
```
- expose an nginx:validate command that can be used to show validation information
- properly reference the invalid nginx config, rather than tell the user that another app's nginx config is invalid when deploying their own app
- allow a user to cleanup bad nginx config files out of band when they are blocking a deploy _without_ requiring knowing where that nginx config is
Note that this may have issues with generated nginx.conf files that depend on other apps or other parts of the nginx config. For now, this is acceptable, though it is something that needs to be field tested.
Closes#3162
This will allow us to kill stale proxy configuration within apps, which is critical during application renames.
- redirect rmdir output to dev-null
- trigger a proxy-clear-config (new trigger) when renaming an application
- The configuration will be rebuilt during the later `ps_rebuild`
Closes#3231
