latest models
Add tests round 1!
Change tests to fail correctly
In progress: Add basic breed statement
Add breeds phase 1: is-breed? and create-breed

Had to also add in some extras like world.getTurtle(id) and whatnot
Add case for orderedturtles!
In Progress: Breeds
Add set-default-shape.

This also has a complete reworking of the underlying breed
representation threaded through it.  I couldn't extricate it into a
separate commit.
Add hatch.

It has a breed too!
Add <breed>-here.
Add <breed>-here part 2
Add Sheep Wolf!

Of course it deviates when you go more than one step!