This change removes all deprecated commands. In many cases, users have been warned for a number of releases before the commands have been removed. All commands that were removed have existing alternatives.
This standardization makes it somewhat easier to read stacktraces as the command names are all uniform, so it will be slightly easier to scan trace output.
This is useful in cases where the command output must be tested, but it is otherwise embedded in a specific part of the dokku core.
As the 'plugin' commands require root, this is safe to add to the core.
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 .
```
