core/consensus: Don't index past the end of our instruction slots.
shared/follow: Fix incorrect variable use causing leader to not be learned.
Add some improved logging.
Add some noisy logging of entering/exiting transactions.

This one may want to be reverted later.
shared/connect: Have the recipient of connections authenticate them.

This is because the client authentication doesn't work right now.
This makes tests insecure, but that's not critical.