It's largely unoptimized, and not yet exclusive to validators, yet has basic
sanity (using message content for ID instead of sender + index).
Fixes bugs as found. Notably, we used a time in milliseconds where the
Tributary expected seconds.
Also has Tributary::new jump to the presumed round number. This reduces slashes
when starting new chains (whose times will be before the current time) and was
the only way I was able to observe successful confirmations given current
surrounding infrastructure.
