BWI Guidance: Multithreaded Monte Carlo Tree Search

This commit introduces the following chnages
  - Use the bwi_rl package for the MCTS implementation. This package is
    a refactored version of Sam's original rl_pursuit package, and has
    diverged from Sam's original code.
  - Changes to allow the code to work with the new Multi-Threaded Monte
    Carlo Tree Search. Two threads cannot use the same random number
    generator.
  - Some simple testers for the monte carlo tree search.
Merge pull request #4 from utexas-bwi/v2

BWI Guidance: Multithreaded Monte Carlo Tree Search