Markov chains in CoffeeScript

CLI:
  markov <subcommand>

  subcommands:
    learn
      outputs a markov model in JSON for text provided on STDIN

      e.g.
        markov learn < tmp/state_of_the_union.txt > tmp/obama.json

    emulate
      generate a sentence using the specified markov matrix

      e.g.
        markov emulate tmp/obama.json