Merge github.com:grpc/grpc into filter-selection

BUILD

Makefile

binding.gyp

build.yaml

doc/load-balancing.md

gRPC.podspec

grpc.gemspec

include/grpc++/impl/codegen/call.h

package.json

src/core/census/mlog.c

src/core/census/mlog.h

src/core/iomgr/iocp_windows.c

src/core/iomgr/iomgr.c

src/core/iomgr/pollset_posix.c

src/core/iomgr/pollset_posix.h

src/core/iomgr/pollset_windows.c

src/core/iomgr/timer.c

src/core/iomgr/timer.h

src/core/surface/completion_queue.c

src/core/transport/chttp2_transport.c