The URLS file is no longer necessary as urls are now generated directly from the app VHOST file.
This also moves all the url generation logic to the domains plugin.
Some things must pull *all* apps vs filtered apps (mostly things that write out config files or install triggers). Using an unflitered list is best.
Also, we default to filtering, which should be what most usage needs.
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 .
```
This helps remove duplication and also ensures that all hosts have a proper setup after running `make copyfiles`
Note that this command is not exposed in help as it is not generally useful to developers
