nsqd: fix BenchmarkProtocolV2Exec panic
Merge pull request #426 from mreiferson/bench_protocol_panic_426

nsqd: benchmarks panics
nsq_to_http, nsq_to_nsq: fix shared request state
nsq_to_nsq, nsq_to_http: per-host upstream host status output
go vet
nsq_to_http, nsq_to_nsq: fix race on handler.counter
Merge pull request #425 from mreiferson/n2n_shared_state_425

apps: fix shared request state
nsqd: healthy flag
review comments