Shaney: implemented equal-probabilities MarkVShaney

Implemented equal-probabilities Shaney with known bug -- multiple
adjacent whitespace characters cause invalid states to be added to
Markov chain.

Added MarkVShaney.clearMarkovChain() to permit training Shaney with
multiple training texts.
Shaney: fixed multiple whitespace bug in equal-probabilities Shaney
Shaney: EqualProbabilitiesShaney.main() can now train on multiple texts