Merge github.com:google/grpc into async-api-new

build.json

src/core/statistics/census_rpc_stats.c

src/core/statistics/census_tracing.c

src/core/statistics/census_tracing.h

src/core/support/env_win32.c

src/core/support/file_posix.c

src/core/support/file_win32.c

src/core/support/string_win32.c

src/core/support/string_win32.h

test/core/statistics/trace_test.c

test/cpp/util/create_test_channel.cc

tools/dockerfile/grpc_cxx/Dockerfile

tools/gce_setup/shared_startup_funcs.sh

vsprojects/vs2013/gpr.vcxproj

vsprojects/vs2013/gpr.vcxproj.filters