Merge github.com:grpc/grpc into faster_timer_pool

BUILD

CMakeLists.txt

Makefile

build.yaml

gRPC-Core.podspec

gRPC-ProtoRPC.podspec

gRPC-RxLibrary.podspec

gRPC.podspec

grpc.def

include/grpc++/grpc++.h

include/grpc++/server_builder.h

include/grpc/grpc.h

package.json

package.xml

src/core/ext/census/intrusive_hash_map.c

src/core/ext/census/intrusive_hash_map.h

src/core/ext/filters/client_channel/channel_connectivity.c

src/core/ext/filters/client_channel/client_channel.c

src/core/ext/filters/client_channel/client_channel.h

src/cpp/common/version_cc.cc