Close body even if it got error http status.

Otherwise, http connections keep open if server
returned error status (e.g. Get returned error).
Merge pull request #13 from ukai/fix_http

Close body even if it got error http status.
PeerPicker uses ring hash to pick peers
Merge pull request #15 from Obvious/master

PeerPicker uses ring hash to more consistently choose peers
HTTPPool increments Group.Stats.ServerRequests
Merge pull request #16 from Obvious/dpup-serverrequests

HTTPPool increments Group.Stats.ServerRequests
consistenthash: replace linear search with binary search

The binary search quickly out-paces the linear search, even for a small
number of shards and replicas.

benchmark          old ns/op    new ns/op    delta
BenchmarkGet8            122          122   +0.00%
BenchmarkGet32           471          137  -70.91%
BenchmarkGet128         5619          254  -95.48%
BenchmarkGet512        90302          406  -99.55%
removed extra unesacping in http pool that screwed up the keys we were using
Merge pull request #26 from dgryski/consistenthash-binary-search

consistenthash: replace linear search with binary search
Merge pull request #27 from EverythingMe/remove_extra_unescaping

removed extra url-unescaping in http pool
changed default number of replicas in http pool hash ring to 50, and fixed hash ring benchmark
Merge pull request #30 from EverythingMe/fix_replicas

changed default number of replicas in http pool hash ring to 50
allow all options of HTTPPool to be specified by users
Merge pull request #33 from fumin/master

allow all options of HTTPPool to be specified by users
merge protobuf move