* swarm, cmd/swarm: address ineffectual assignments

* swarm/network: remove unused vars from testHandshake

* swarm/storage/feed: revert cursor changes

* RequestFromPeers does not use peers marked as lightnode

* fix warning about variable name

* write tests for RequestFromPeers

* lightnodes should be omitted from the addressbook

* resolve pr comments regarding logging, formatting and comments

* resolve pr comments regarding comments and added a missing newline

* add assertions to check peers in live connections

* core: speed up GenerateChain

Use a mock implementation of ChainReader instead of creating
and destroying a BlockChain object for each generated block.

* eth/downloader: speed up tests by generating chain only once

This change reworks the downloader tests so they share a common test
blockchain instead of generating a chain in every test. The tests are
roughly twice as fast now.

* signer: remove ineffectual assignments

* signer: remove ineffectual assignments

* downloader: measure successfull deliveries, not failed

* downloader: fix typos

* swarm: Better syncing and retrieval option definition

* swarm/network/stream: better comments

* swarm/network/stream: addressed PR comments

* swarm: modify context key

* gofmt sctx.go

* swarm: clean up unused private types and functions

Those that were identified by code inspection tool.

* swarm/storage: move/add Proximity GoDoc from deleted private function

The mentioned proximity() private function was deleted in:
1ca8fc1e6fa0ab4ab1aaca06d6fb32e173cd5f2f

* p2p/protocols: introduced protocol accounting

* p2p/protocols: added TestExchange simulation

* p2p/protocols: add accounting simulation

* p2p/protocols: remove unnecessary tests

* p2p/protocols: comments for accounting simulation

* p2p/protocols: addressed PR comments

* p2p/protocols: finalized accounting implementation

* p2p/protocols: removed unused code

* p2p/protocols: addressed @nonsense PR comments

* cmd/clef: replace password arg with prompt (#17829)

Entering passwords on the command line is not secure as it is easy to recover from bash_history or the process table.
1. The clef command addpw was renamed to setpw to better describe the functionality
2. The <password> argument was removed and replaced with an interactive prompt

* cmd/clef: remove undeclared variable

   __
 <(o )___
  ( ._> /
   `---' 

This fixes the import cycle build error in core/vm tests.
There is no need to refer to core/vm for a type definition.

This adds the global accumulated refund counter to the standard
json output as a numeric json value. Previously this was not very
interesting since it was not used much, but with the new sstore
gas changes the value is a lot more interesting from a consensus
investigation perspective.

* swarm/network/stream: disambiguate chunk delivery messages (retrieval vs syncing)

* swarm/network/stream: addressed PR comments

* swarm/network/stream: stream protocol version change due to new message types in this PR

* first impl of eth_getProof

* fixed docu

* added comments and refactored based on comments from holiman

* created structs

* handle errors correctly

* change Value to *hexutil.Big in order to have the same output as parity

* use ProofList as return type

* swarm: Lightnode mode: disable sync, retrieve, subscription

* swarm/network/stream: assign error and check in one line

* swarm: restructured RegistryOption initializing

* swarm: empty commit to retrigger CI build

* swarm/network/stream: Added comments explaining RegistryOptions

This is no longer needed because Go uses all CPUs
by default. The change allows setting GOMAXPROCS in environment if needed.

The changes allow building WebAssembly applications which use ethclient.Client.

This change extends the peer metrics collection:

- traces the life-cycle of the peers
- meters the peer traffic separately for every peer
- creates event feed for the peer events
- emits the peer events