Decouple resource set name and path

[tazjin]

Currently the path from which a resource set's files are loaded is inferred from the name of the resource set.

In some situations, such as importing the same resource set multiple times with different configuration, the user may want to split paths and names. This should be supported:

- name: api-europe
  path: some-api
  values:
    location: europe
- name: api-asia
  path: some-api
  values:
    location: asia

thus making it possible to use --include / --exclude api-asia for example.