Teach the unit tests how to use the z3 bidder. 13% of unit tests pass. :p
Teach the z3 bidder how to open 1NT, and teach the Makefile about the z3 bidder.
Now that we have the unit tests we don't need the inline code in bidder3.py
Fix a bad != in priority_for_call_and_hand causing inversion of conditional priority handling.