VTGate V2 implementation and sandbox test improvement
Merge branch 'master' into liguo

Conflicts:
	go/vt/vtgate/proto/vtgate_proto.go
Update VTGate V2 with keyspaceid and keyrange queries
Merge branch 'master' into liguo, generate additional bson files

Conflicts:
	go/vt/key/key.go
	go/vt/vtgate/proto/vtgate_proto.go
	go/vt/vtgate/scatter_conn_test.go
	go/vt/vtgate/shard_conn_test.go
EntityIdsQuery related change (WIP)
Merge branch 'master' into liguo
Add url to flush logs to test environment module.
Make the vtocc queryservice test more explicit about its depeendencies.
Address comments
Merge branch 'master' into liguo
Add ExecuteEntityIds() to VTGate V2
Merge branch 'vtocc'
gorpc: Change ssl timeout to be different from normal

The different error message will help trouble shoot the root
cause of problems better.
Also, fixed some typos.
Merge branch 'master' into monitoring
Fixing race conditions in zkconn.

A client might be getting a conn from metaconn, and then
use it for queries. It might get closed at the same time.
So it needs to be protected by a mutex.
Merge branch 'master' into replication
Merge branch 'master' into liguo
Allowing multiple Close in zkconn.
Merge branch 'master' of github.com:youtube/vitess
servenv: support for lameduck-period