* Fix "sgn" in fift; fix marking infinite loops as noterurn in func
* TON-P1-1: Remove unused catchain queries
* TON-P1-15: Avoid synchronization with self
* TON-P1-3, TON-P1-17: Disallow more than one candidate per src per round (to prevent flood), add checks to process_broadcast
* TON-P1-10: Fix fast/slow attempts
* TON-P1-14: Add named constants
* TON-P1-18, TON-P1-19: Alloc temporary memory in the same way as persistent memory
* TON-P1-20: Add comment to choose_blocks_to_approve
* TON-P1-16: Avoid creating two catchain blocks on need_new_block
* TON-P1-8: Add some validation to validator-engine parameters
* TON-P1-6: Don't allow sending the same block many times
Many requests for the same block are not unusual (however, there's no need to answer them all)
* TON-P1-2: Enable prohibiting dependencies from blamed nodes (2.7.5 in CatChain doc), fix processing blame proofs
* Best practices
bp-6: Fix incorrect warning
bp-7: Remove unused code
bp-8: Bring back PerfWarningTimer logging (only when no callback)
bp-9: Remove unnecessary condition
bp-11: Remove commented-out code
bp-13: Divide code in validator-session-state
Adherence to Specification: Fix typo
