Merge branch 'master' of github.com:grpc/grpc into compression

BUILD

Makefile

README.md

build.json

gRPC.podspec

include/grpc/grpc.h

include/grpc/support/string_util.h

src/core/channel/channel_args.c

src/core/debug/trace.c

src/core/debug/trace.h

src/core/httpcli/format_request.c

src/core/httpcli/httpcli.c

src/core/httpcli/httpcli_security_connector.c

src/core/iomgr/endpoint_pair_posix.c

src/core/iomgr/iomgr.c

src/core/iomgr/resolve_address_posix.c

src/core/iomgr/resolve_address_windows.c

src/core/iomgr/sockaddr_utils.c

src/core/iomgr/socket_windows.c

src/core/iomgr/tcp_client_posix.c