Merge remote-tracking branch 'upstream/master' into mock

.travis.yml

Makefile

gRPC.podspec

include/grpc++/config.h

include/grpc++/impl/call.h

include/grpc++/server.h

include/grpc++/server_builder.h

include/grpc/grpc.h

src/compiler/cpp_generator.cc

src/core/channel/context.h

src/core/iomgr/endpoint_pair_windows.c

src/core/iomgr/iocp_windows.c

src/core/iomgr/iomgr_windows.c

src/core/iomgr/pollset_kick_windows.h

src/core/iomgr/pollset_windows.c

src/core/iomgr/pollset_windows.h

src/core/iomgr/socket_windows.c

src/core/iomgr/socket_windows.h

src/core/iomgr/tcp_client_windows.c

src/core/iomgr/tcp_posix.c