Merge github.com:grpc/grpc into fix_errors

doc/cpp/perf_notes.md

doc/interop-test-descriptions.md

include/grpc++/grpc++.h

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

src/core/ext/README.md

src/core/ext/client_channel/channel_connectivity.c

src/core/ext/client_channel/subchannel.c

src/core/ext/lb_policy/grpclb/grpclb.c

src/core/ext/resolver/README.md

src/core/ext/resolver/dns/native/dns_resolver.c

src/core/ext/transport/README.md

src/core/ext/transport/chttp2/README.md

src/core/ext/transport/chttp2/transport/chttp2_transport.c

src/core/lib/README.md

src/core/lib/channel/README.md

src/core/lib/channel/deadline_filter.c

src/core/lib/channel/deadline_filter.h

src/core/lib/channel/handshaker.c

src/core/lib/iomgr/README.md

src/core/lib/iomgr/tcp_client_posix.c