Load Apps Sandboxed

- Based on suggestions from hswolff loading with a Module class approach
- Loads relative modules in child sandboxes
Merge pull request #2091 from jgable/sandboxApps

Load Apps Sandboxed
Merge branch 'master' of https://github.com/TryGhost/Ghost
Updated Ghastly to demo the site a bit. It's still unfinished.