Add JS code for deterministic counterbalancing.
Add Python code for deterministic counterbalancing.
Add to JSON schema for counterbalancing.
Add counterbalance to README.

Also a couple other notes.
Fix bugs in JS counterbalance code.
Fix Python code for counterbalancing.
Fix bug in Python Component.new.

After renaming id to id_str, new was broken.
Added a test file, need more tests.
Remove breakoff code.

I will probably want to add the option again but it will probably be a
while, and it will have to be handled differently from before due to the
new way of recording the final question.