README: Change gitter badge to discord

cmd/clef: fix incorrect file permissions for secrets.dat

Co-authored-by: Janos Guljas <janos@resenje.org>
Co-authored-by: Balint Gabor <balint.g@gmail.com>
Co-authored-by: Anton Evangelatov <anton.evangelatov@gmail.com>
Co-authored-by: Viktor Trón <viktor.tron@gmail.com>

* swarm/storage: remove redundant increments for dataIdx and entryCnt

* swarm/storage: add Delete to LDBStore

* swarm/storage: wait for garbage collection

* swarm/network: simplify kademlia/hive; rid interfaces

* swarm, swarm/network/stream, swarm/netork/simulations,, swarm/pss: adapt to new Kad API

* swarm/network: minor changes re review; add missing lock to NeighbourhoodDepthC

cmd/swarm: password threw on upload manifest

Signed-off-by: YaoZengzeng <yaozengzeng@zju.edu.cn>

* swarm/storage/encryption: async segmentwise encryption/decryption

* swarm/storage: adapt hasherstore to encryption API change

* swarm/api: adapt RefEncryption for AC to new Encryption API

* swarm/storage/encryption: address review comments

consensus/clique: only trust snapshot for genesis or les checkpoint

Makes Interface interface a bit more stateless and abstract.

Obviously this change is dictated by EVMC design. The EVMC tries to keep the responsibility for EVM features totally inside the VMs, if feasible. This makes VM "stateless" because VM does not need to pass any information between executions, all information is included in parameters of the execute function.

The template was not grammatical to me as it was. I have edited the language a tiny bit to make the close comment more clear and less abrasive.

Fixes #17581

Fixes #17557

This commit does a few things at once:

- Updates the tests to contain the latest data from ethereum/tests repo.
- Enables Constantinople state tests. This is needed to be able to
  fuzz-test the evm with constantinople rules.
- Fixes the error in opSAR that we've known about for some time. I was
  kind of saving it to see if we hit upon it with the random test
  generator, but it's difficult to both enable the tests and have the
  bug there -- we don't want to forget about it, so maybe it's better
  to just fix it.

This is an attempt to fix the flaky consensus/ethash tests under macOS.

This fixes an issue with websocket ping frame handling.