Merge github.com:grpc/grpc into epex5

BUILD

CMakeLists.txt

Makefile

binding.gyp

build.yaml

config.m4

config.w32

gRPC-Core.podspec

grpc.gemspec

package.xml

src/core/ext/census/intrusive_hash_map.c

src/core/ext/census/intrusive_hash_map.h

src/core/ext/census/intrusive_hash_map_internal.h

src/core/lib/http/httpcli.c

src/core/lib/http/httpcli_security_connector.c

src/core/lib/security/transport/security_connector.c

src/core/lib/security/transport/security_handshaker.c

src/node/README.md

src/node/index.js

src/node/src/client.js