Use Node.contains() in LandmarksFinder
Use Node.contains() in LandmarksFinder

This doesn't make any significant performance improvement (as per the
results below), but it does simplify the code. The results below are a
control, then tests for both Node.compareDocumentPosition() and
Node.contains(). As the latter results in simpler code and performance
is the same (as one might expect), it is adopted.

==> r0-control-a.json <==
{
  "abootstrap": {
    "mean": 94,
    "standardDeviation": 20
  },
  "amazon": {
    "mean": 9.6,
    "standardDeviation": 3.3
  },
  "ars": {
    "mean": 5.4,
    "standardDeviation": 2.5
  },
  "bbcnews": {
    "mean": 8.8,
    "standardDeviation": 3.5
  },
  "googledoc": {
    "mean": 1.3,
    "standardDeviation": 0.76
  }
}
==> r1-control-b.json <==
{
  "abootstrap": {
    "mean": 100,
    "standardDeviation": 20
  },
  "amazon": {
    "mean": 12,
    "standardDeviation": 3.6
  },
  "ars": {
    "mean": 5.2,
    "standardDeviation": 2.5
  },
  "bbcnews": {
    "mean": 8.6,
    "standardDeviation": 3.3
  },
  "googledoc": {
    "mean": 1.4,
    "standardDeviation": 1.9
  }
}
==> r2-contains-a.json <==
{
  "abootstrap": {
    "mean": 95,
    "standardDeviation": 20
  },
  "amazon": {
    "mean": 14,
    "standardDeviation": 3.3
  },
  "ars": {
    "mean": 5.2,
    "standardDeviation": 2.2
  },
  "bbcnews": {
    "mean": 9.1,
    "standardDeviation": 3.4
  },
  "googledoc": {
    "mean": 1.4,
    "standardDeviation": 0.73
  }
}
==> r3-contains-b.json <==
{
  "abootstrap": {
    "mean": 100,
    "standardDeviation": 22
  },
  "amazon": {
    "mean": 10,
    "standardDeviation": 3.3
  },
  "ars": {
    "mean": 5.3,
    "standardDeviation": 2.6
  },
  "bbcnews": {
    "mean": 8.7,
    "standardDeviation": 3.1
  },
  "googledoc": {
    "mean": 1.3,
    "standardDeviation": 0.68
  }
}
==> r4-compareDocumentPosition-a.json <==
{
  "abootstrap": {
    "mean": 100,
    "standardDeviation": 21
  },
  "amazon": {
    "mean": 11,
    "standardDeviation": 3.4
  },
  "ars": {
    "mean": 5.5,
    "standardDeviation": 2.2
  },
  "bbcnews": {
    "mean": 8.7,
    "standardDeviation": 3.1
  },
  "googledoc": {
    "mean": 1.4,
    "standardDeviation": 1.6
  }
}
==> r5-compareDocumentPosition-b.json <==
{
  "abootstrap": {
    "mean": 98,
    "standardDeviation": 20
  },
  "amazon": {
    "mean": 10,
    "standardDeviation": 3.6
  },
  "ars": {
    "mean": 4.9,
    "standardDeviation": 2.2
  },
  "bbcnews": {
    "mean": 8.6,
    "standardDeviation": 3.4
  },
  "googledoc": {
    "mean": 1.4,
    "standardDeviation": 1.6
  }
}

Closes #125.

matatk/landmarks,matatk/landmarks,matatk/landmarks