Simplify names now confdir is defined for templating
Remove config.ru notification to Nginx::Vhost

The Nginx virtual host should not care about the config.ru file, this
file is only relevant to the Rack compatible server being used, either
Thin or Unicorn.
Subscribe thin::app and unicorn::app to config.ru

When this file changes the Thin or Unicorn server needs to be restarted.
Fix server::unicorn Nginx::{Vhost => Unicorn} reference.