Merge branch 'master' of https://github.com/grpc/grpc into ALL-the-things

BUILD

CMakeLists.txt

CODE-OF-CONDUCT.md

Makefile

PATENTS

binding.gyp

build.yaml

config.m4

config.w32

gRPC-Core.podspec

grpc.gemspec

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

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

package.xml

...rs/client_channel/resolver/dns/c_ares/dns_resolver_ares.c

.../client_channel/resolver/dns/c_ares/grpc_ares_ev_driver.h

...t_channel/resolver/dns/c_ares/grpc_ares_ev_driver_posix.c

...rs/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.c

...rs/client_channel/resolver/dns/c_ares/grpc_ares_wrapper.h

..._channel/resolver/dns/c_ares/grpc_ares_wrapper_fallback.c