Merge branch 'master' into objective_c_interop_tests

BUILD

Makefile

build.json

include/grpc/support/tls_pthread.h

src/core/support/tls_pthread.c

src/node/interop/interop_client.js

src/node/test/interop_sanity_test.js

src/php/ext/grpc/call.c

src/php/ext/grpc/call.h

src/php/ext/grpc/completion_queue.c

src/php/ext/grpc/completion_queue.h

src/php/ext/grpc/config.m4

src/php/ext/grpc/php_grpc.c

src/php/ext/grpc/server.c

src/php/ext/grpc/server.h

tools/dockerfile/grpc_java_android/Dockerfile

tools/dockerfile/grpc_java_android/README.md

vsprojects/gpr/gpr.vcxproj

vsprojects/gpr/gpr.vcxproj.filters