* Add "drop by score" ability to PeerPool.
Add tests.
Fix syncmanager queue to start from most fresh data.
* Fix endless cycle at the end of syncing process.
* switch out quadratically scaling and wasteful attestation in state_sim to attest only to exactly the correct slots; avoid pointless committee index interconversion for 9-10x increase in state_sim speed at d:release, 60k validators, and validate=off
* remove debugechos