ProblemTester functions

term_test() checks output from determineLife() against problem states.
test_problem() uses ML models and min-max tree to try to solve the
problem, checking against terminal states. Fails after 2*max problem
path length moves have been taken.
load_model() convenient for loading ML models
main() function takes two parameters: modelDir and problemDir (/train or
/dev).
Added convert_csv_for_terminal_test
Removed dup DistanceFromCenterFeature
Implemented __hash__() and __eq__()

For convenient use of board instance in sets or dictionaries, easy test
for equivalent states.
Added model, fixed bestChild (hopefully)
Added load_problem_start for UI init
Little fix isBlack -> isblack
Merge branch 'develop' of https://github.com/RU-CS530-Go-Team/GoLD into develop