* fix replays stalling processing
Occasionally, attestations will arrive that vote for a target derived
either from the finalized block or earlier. In these cases, Nimbus would
replay the state transition of up to 32 epochs worth of blocks because
the finalized state has been pruned, delaying other processing and
leading to poor inclusion distance.
* put cheap attestation checks before forming EpochRef
* check that attestation target is not from an unviable history with
regards to finalization
* fix overly aggressive state pruning removing the state close to the
finalized checkpoint resulting in rare long replays for valid
attestations
* log long replays
* harden logging and traversal of nil BlockSlot
* simplify target check
no need to lookup target in chain dag again
* fixup
* fixup
* refactor slot loop
* fix attestations being sent out early when _any_ block arrives (as
opposed to the block for the "correct" slot)
* fix attestations being sent out late when block already arrived
* refactor slot processing loop
* shutdown if clock moves backwards significantly
* fix docs
* notify caller whether the block actually arrived
* fix several memory leaks due to temporaries not being reset during
init
* avoid massive main() function with lots of stuff in it
* disable nim-prompt (unused)
* reuse validator pool instance in eth2_processor
* style cleanup
* database state storage benchmarking via ncli_db
* more cleanups from immutable validator state branch
* unexport some eth2_network constants and remove unused variables/templates
* make two PeerScore constants public
Tests have been moved to the Makefile and the test binaries are built in
parallel.
The Nim compilation scheme has been moved to a script and adapted to
work with different binaries being built in parallel from the same main
source file (think minimal/mainnet tests).
* Create CLI tool for slashing export
* Use SQLite as a DB instead of a KV-store
* Keeps v1 and v2 DBs around
* Uses the same schema as Lighthouse v1.1.0
* Passes all interchange tests + skeleton of finalization pruning
* Removes tests that would violate v5 / minimal slashing DB and MinSlot rules
* Migration tool added using low-watermark scheme for faster migration of large number of validators