refs https://github.com/TryGhost/Team/issues/65
- this is just the first optimisation regarding relative/absolute urls
- the full strike will happen when i start with the url utility re-write
- for now: there will be only one subscriber of url events -> the sitemaps service
- the sitemaps service outputs absolute urls
- we don't want to receive an url event and ask the url service again to get an absolute version of the url
097e1d1fac