Merge github.com:grpc/grpc into direct-calls

.gitmodules

BUILD

CMakeLists.txt

Makefile

binding.gyp

build.yaml

config.m4

...ples/csharp/helloworld/Greeter/Properties/AssemblyInfo.cs

...sharp/helloworld/GreeterClient/Properties/AssemblyInfo.cs

...sharp/helloworld/GreeterServer/Properties/AssemblyInfo.cs

.../csharp/route_guide/RouteGuide/Properties/AssemblyInfo.cs

...p/route_guide/RouteGuideClient/Properties/AssemblyInfo.cs

...p/route_guide/RouteGuideServer/Properties/AssemblyInfo.cs

gRPC-Core.podspec

grpc.gemspec

include/grpc/impl/codegen/port_platform.h

package.xml

src/core/ext/client_config/client_channel.c

src/core/ext/client_config/http_connect_handshaker.c

src/core/ext/client_config/http_connect_handshaker.h