How to archive systems

We need to decide how we want to "archive" systems when they are retired.
- [ ] Hardware definitions: we could keep a table of retired systems, or add a field which can indicate it's retired. Thoughts?
- [ ] Info from system.py: I think it might be nice to keep an idea of what the software stack was at the time of arrival, compiler versions etc. I can see us tracking those over time at some point