Merge pull request #5098 from a-veitch/base_log

BUILD

Makefile

binding.gyp

build.yaml

gRPC.podspec

grpc.gemspec

package.json

src/core/census/log.c

src/core/census/log.h

src/python/grpcio/grpc_core_dependencies.py

test/core/census/log_test.c

tools/doxygen/Doxyfile.core.internal

tools/run_tests/sources_and_headers.json

tools/run_tests/tests.json

vsprojects/buildtests_c.sln

vsprojects/vcxproj/grpc/grpc.vcxproj

vsprojects/vcxproj/grpc/grpc.vcxproj.filters

vsprojects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj

...jects/vcxproj/grpc_unsecure/grpc_unsecure.vcxproj.filters

...ects/vcxproj/test/census_log_test/census_log_test.vcxproj