DONE:
1. Fixed and checked the metric computation.
2. Changed a bit the class organization for MDPs and states, to ensure
proper usage of its member fields.

TODO:
1. A bit more commenting
2. Some magic numbers to take care of - numerical stability issues
appeared now that we're using Doubles instead of Integers
3. Set up the iterative search algorithm over couplings (To discuss on
June 2nd)