Merge branch 'master' into cq_create_api_changes

.gitignore

BUILD

CMakeLists.txt

Makefile

bazel/cc_grpc_library.bzl

bazel/generate_cc.bzl

bazel/grpc_build_system.bzl

binding.gyp

build.yaml

config.m4

doc/combiner-explainer.md

doc/g_stands_for.md

doc/status_ordering.md

examples/csharp/helloworld-from-cli/global.json

gRPC-Core.podspec

gRPC-ProtoRPC.podspec

gRPC-RxLibrary.podspec

gRPC.podspec

grpc.def

grpc.gemspec