Merge branch 'cleaner-posix' into cleaner-posix2

BUILD

Makefile

binding.gyp

build.yaml

gRPC.podspec

grpc.def

grpc.gemspec

include/grpc++/support/channel_arguments.h

include/grpc/grpc_security.h

include/grpc/impl/codegen/grpc_types.h

include/grpc/support/avl.h

include/grpc/support/useful.h

package.json

src/core/census/log.c

src/core/census/log.h

src/core/channel/channel_args.c

src/core/channel/channel_args.h

src/core/client_config/connector.c

src/core/client_config/connector.h

src/core/client_config/subchannel.c