Merge branch 'master' of github.com:grpc/grpc into the-purge-2

BUILD

Makefile

build.json

examples/pubsub/main.cc

examples/pubsub/publisher_test.cc

examples/pubsub/subscriber_test.cc

include/grpc++/completion_queue.h

include/grpc++/credentials.h

include/grpc++/impl/grpc_library.h

include/grpc++/server.h

src/cpp/client/channel.h

src/csharp/Grpc.Core/Internal/CallSafeHandle.cs

src/csharp/Grpc.Core/Internal/ServerSafeHandle.cs

src/csharp/Grpc.Core/Server.cs

src/csharp/Grpc.Examples.MathServer/MathServer.cs

...rp/Grpc.IntegrationTesting/Grpc.IntegrationTesting.csproj

src/ruby/ext/grpc/rb_call.c

src/ruby/grpc.gemspec

src/ruby/lib/grpc.rb

src/ruby/lib/grpc/generic/active_call.rb