Merge branch 'minimal' of github.com:ctiller/grpc into minimal

BUILD

CMakeLists.txt

Makefile

binding.gyp

build.yaml

config.m4

doc/PROTOCOL-HTTP2.md

gRPC-Core.podspec

grpc.gemspec

package.xml

src/core/ext/census/gen/trace_context.pb.h

src/core/ext/census/trace_label.h

src/core/ext/census/trace_propagation.h

src/core/ext/census/trace_status.h

src/core/ext/census/trace_string.h

src/core/ext/census/tracing.h

src/core/ext/filters/client_channel/README.md

src/core/ext/filters/client_channel/channel_connectivity.c

src/core/ext/filters/client_channel/client_channel.c

src/core/ext/filters/client_channel/client_channel.h