Support vagrant in both kick.py and run.py

[matze]

So far, the kick.py and run.py scripts have only been of use in production environment, which causes both of them to be not testable without prior modification, amongst other downsides. After #112 and #2200 are done, we can easily change that and adopt both scripts for our development environment as well - with only a minimal portion remaining environment-specific.

The idea is to change the behavior sp that --local does not cause the local hosts.yaml file to be used, but vagrant(1) instead of ssh(1) in the first place. This should be fairly easy, because the Vagrantfile already utilizes the local hosts.yaml to set up the development boxes.