added detailed rollup naming

This prepends the domain to the application name. Useful for NR accounts with multiple sites/domains
@g000m I might not follow this. Won't this repeat the `$app_name` at the front _and_ back, so it might look like `hostname.org ajax hostname.org`?

FYI: we follow WordPress' code standards for spacing rules. See http://kitchen.gigaom.com/2014/07/17/our-code-standards/