Disambiguate identical file names at different points in hierarchy

[tsiq-karold]

As an example, let's take this directory hierarchy:

scenarios
  foo.grooy
  stuff
    foo.groovy

If I run webtau with scenarios/foo.groovy scenarios/stuff/foo.groovy then in the html report, I just get two sections with a foo.groovy file name which is confusing. We should include the full name, perhaps relative to something though I'm not sure what the something ought to be :)

[MykolaGolubyev]

@tsiq-karold hmm, not sure if someone fixed it in the other PRs, but I can't reproduce it now with 1.41.
Could you please give it a go again?