Merge pull request #14540 from bas-vk/whisper-api

cmd/geth/config.go

cmd/geth/consolecmd.go

cmd/geth/main.go

cmd/geth/usage.go

cmd/utils/flags.go

cmd/wnode/main.go

internal/web3ext/web3ext.go

mobile/geth.go

rpc/client.go

vendor/golang.org/x/sync/LICENSE

vendor/golang.org/x/sync/PATENTS

vendor/golang.org/x/sync/syncmap/map.go

vendor/vendor.json

whisper/mailserver/server_test.go

whisper/shhclient/client.go

whisper/whisperv5/api.go

whisper/whisperv5/api_test.go

whisper/whisperv5/config.go

whisper/whisperv5/doc.go

whisper/whisperv5/envelope.go