GitLab

This changed a while ago in one of the refactoring steps so some of the scripts
were broken.

- adds description for netperf experiment
- reformat local.py
- reformat results/netperf.py

- classes ExpEnv and ExpOutput had to be moved to prevent circular imports
- reformat common.py

moved functions:
- create_basic_hosts()
- create_multinic_hosts()
- create_dctcp_hosts()

This enables qemu hosts to still run if KVM is not available, albeit
much slower.

For qemu the syntax changed, and network simulators dropped the
alternative synchronization protocol parameter.

This speeds up base image build significantly