ChRIS portable conclusive documentation

# ChRIS "portable" conclusive documentation

We need completely explicit and well presented documentation taking a reader from an Ubuntu ISO image on the one hand, to a fully instantiated ChRIS VM at the end, complete with Orthanc integration, working pacs_pull/push, and several working plugins -- assuming a **local** runtime (i.e. no cluster backend).
## Start
- Ubuntu ISO and VM setup
## Intermediate
- Database setup
- User setup
- git checkout
## Plugins
- (need list of plugins)
## Debugging
- Tips on how to debug a plugin
## Orthanc integration
- Working Orthanc instance
## Data/user trees on host and configuration/cross mount from VM to host.

Due to the small size of the VM, all data and user dirs must by necessity reside **outside** the VM, typically on the host. This is most easily accomplished on Linux and Mac hosts. Windows hosts will require careful testing.

@NicolasRannou and @rpienaar