MARKOV: Put the Markov functions into a class wrapper and created a way ...

...to work around issues with multiple eigenvalues near unity to prevent nonstationary distirbutions from being considered stationary.

If you get a chance to look, let me know what you think.  There are some minor things that I plan on changing (right now I'm squeezing everything so that it works with the tests that people had already written, but eventually I hope to clean that up or change the tests).  This is more to get a working version into master and get some feedback of what people think of using a class as a wrapper.