This reduces duplication and allows users to rely on global arguments to generate most labels needed.
The 'commit' command cannot have global arguments because the whitespace within the label change breaks string-based interpolation, and shell arrays cannot be exported.
This change allows operators to specify a DOCKER_BIN environment variable. This will specify a binary to run when executing docker, which is useful in cases where the 'docker' command being run must be modified in a way that would otherwise be invasive to Dokku, but minimalistic if done within a wrapper.
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 .
```
These will be killed on a cron schedule, allowing us to ensure old containers don't run once memory pressure clears up - even across restarts.
Closes#3225
This can be useful in cases where a developer wishes to see what error messages are available for a failed deploy, but does not wish to spelunk around `docker ps -a` output.
Note that the logs are not made available once a further deploy is triggered, or after the containers have been garbage collected.
