Merge github.com:grpc/grpc into bind-server-twice

Makefile

build.yaml

include/grpc/compression.h

src/core/client_config/resolvers/sockaddr_resolver.c

src/core/compression/algorithm.c

src/core/compression/message_compress.c

src/core/iomgr/pollset_multipoller_with_epoll.c

src/core/iomgr/pollset_multipoller_with_poll_posix.c

src/core/iomgr/pollset_posix.c

src/core/iomgr/pollset_posix.h

src/core/iomgr/wakeup_fd_posix.c

src/core/iomgr/wakeup_fd_posix.h

src/core/json/json_reader.c

src/core/json/json_string.c

src/core/transport/metadata_batch.c

src/core/transport/metadata_batch.h

src/csharp/Grpc.Core.Tests/ClientServerTest.cs

src/csharp/Grpc.Core.Tests/MetadataTest.cs

src/ruby/bin/apis/pubsub_demo.rb

src/ruby/ext/grpc/rb_call.c