Explicit demo projects

[tokejepsen]

Goal
Reduce the time spent for initial demo setup.

Motivation
As a first time user it would be nice to get into the server with some demo data as quickly as possible. This could be done by just setting up the demo_commercial project instead of the larger demo_big_episodic and demo_big_feature`.

Implemention
manage [project_name] > to explicitly setup one of the demo projects.
manage demo > still sets up all demo projects.