Merge github.com:grpc/grpc into grand-unified-closures

BUILD

CMakeLists.txt

Makefile

binding.gyp

build.yaml

config.m4

doc/fail_fast.md

doc/wait-for-ready.md

examples/php/run_greeter_client.sh

gRPC-Core.podspec

grpc.gemspec

include/grpc++/grpc++.h

include/grpc++/impl/codegen/client_context.h

include/grpc++/impl/codegen/server_context.h

include/grpc++/impl/server_builder_plugin.h

include/grpc/impl/codegen/grpc_types.h

package.xml

src/core/ext/census/gen/README.md

src/core/ext/census/gen/trace_context.pb.c

src/core/ext/census/gen/trace_context.pb.h