KMeans Classifier Implementation

Examples:

Generate 1000 rows of test data, clustered around 3 points:

    # generate test data
    ./gen-data.rb 1000 3 > example.dat

    # classify data, plot results as png
    ./km-test kmeans example.dat example.png

Run all tests and save best clustering in current directory along with
PNGs of results:

    for i in tests/*dat; do
      # build paths
      png_path=kmeans-$(basename ${i/dat/png})
      dst_path=kmeans-$(basename $i)

      # run test
      echo $i
      ./km-test kmeans $i $png_path > $dst_path
    done