Switching to a new branch to test a different fix.  The idea here is to leave agent traits as a pure set, like
the extensible model.  Only the trait trees themselves have the chain structure.  This allows the rest of the
extensible model to be exactly the same, AND it facilitates a clean, verifiable way of letting agents learn
either leaf or prerequisite traits.
Basic tree structured rule is operating, but it gets stuck when convergence is far from occurring but
nobody has prereqs for each other.
axelrod-ct-14 Much healthier version of tree structured model, needs implementation of learning "deepest required prequisite that I miss" and should be interesting.
Basic semantic model complete - needs data objection and new finalization method
and more observational tools to see what the resulting cultures look like in terms
of trait trees.