ZF2-288: Support optional subdomain pieces in Hostname route
We often develop on domains like http://local.www.example.com, where http://www.example.com is our production URL. It would be nice to match that where the local part is optional (route: :environment.www.example.com).
Another use case is our staging environment. We use Akamai to make wildcard subdomains all go to staging environment. So we will have urls like http://some-branch.stage.www.example.com or http://another-branch.stage.www.example.com. It would be nice to optionally match against a route like :branch.:environment.www.example.com