Regarding the question about `replaces` it currently is assumed to be a single item:
https://github.com/opscode/omnibus-ruby/blob/master/lib/omnibus/project.rb#L470

That being said, according to the [FPM docs](https://github.com/jordansissel/fpm/wiki) the `--replaces` flag can be be specified multiple times.

We could update the project DSL to allow the `replaces` keyword to be called multiple times (like `dependency`). So the new code might look something like:

```ruby
replaces "chef-server"
replaces "chef-server-core"
```