Notes to myself on optimization

Also adding things like @Override for code clarity
Mucking around with the heuristic

I've developed some test cases that correspond to "accurate" heuristics.
One problem I discovered with the current heuristic is that, in some
cases, the solution would overestimate some solutions.  I think I might
have to do something involving two steps for things done to variables...
Preparing for commit
Merge branch 'story' of https://github.com/thomaswp/tuxblocks into story
Made better heuristic

This heuristic can solve problems up to (0-indexed) difficulty 3, which
is better than the previous one which got stuck on difficulty 2
problems.  It's not perfect, but it's a start