Find a better organization for test session template / constellation / node definitions and results

[jernst]

I'm thinking:

Node and constellations:

• we should have a way of definition nodes/instances in files independently of constellations
• we should have a way of combining multiple files defining nodes, plus role names, into a file defining a constellation

Production test plans vs. example test plans: It's important that we have example test plans in git so new users can start using this faster. But we also need to be able to easily update production test plans when, for example, new types of nodes appear or tests are added

• so we need to check in scripts that can reproducibly create the same test plan. make comes to mind.

[jernst]

Got that now.