Adds Markov chain for terms-based model.
Adds Markov chain for terms-based model.

``TermsBasedMarkovChain`` uses the terms-based model for Monte Carlo
simulation.

git-svn-id: 6391b798f55e3e4f5184bc6d113ebedc82009d5e@3723 1fbec0df-f6b4-4bca-857c-de90862b47bd

gotgenes/BiologicalProcessNetworks