50:50 split algorithm now works in following way:
- On client configuration change, membership change or disconnect wait
till membership is stable (= all client configuration node list are
equal, and all partitions has equal information).
- Choose best partition >= 50%
- If no such partition exists, send NACK to all clients
- Send NACK to all clients who should receive NACK
- After all clients who should receive NACK confirm vote reception, send
ACK to all clients who should get ACK
This ensures that there are never two partitions with ACK and it has
much better behavior than previous version, because if tie-breaker
partition is not connected, other partition gets ACK.
Signed-off-by: Jan Friesse <jfriesse@redhat.com>
