Merge github.com:grpc/grpc into api_fuzzer

Makefile

build.yaml

grpc.gemspec

include/grpc/support/string_util.h

src/compiler/cpp_generator.cc

src/compiler/cpp_generator.h

src/compiler/cpp_plugin.cc

src/core/lib/iomgr/tcp_server_posix.c

src/core/lib/iomgr/tcp_server_windows.c

src/core/lib/iomgr/udp_server.c

src/core/lib/profiling/basic_timers.c

src/core/lib/support/alloc.c

src/core/lib/support/log_linux.c

src/core/lib/support/thd_posix.c

src/core/lib/surface/byte_buffer.c

src/core/lib/tsi/fake_transport_security.c

src/core/lib/tsi/ssl_transport_security.c

src/core/lib/tsi/transport_security.c

src/ruby/lib/grpc/generic/client_stub.rb

templates/grpc.gemspec.template