Merge branch 'master' of github.com:grpc/grpc into credentials_naming_and_cleanup

include/grpc++/create_channel.h

include/grpc++/credentials.h

src/compiler/csharp_generator.cc

src/compiler/csharp_generator.h

src/core/census/grpc_filter.c

src/core/transport/chttp2/stream_lists.c

src/core/transport/metadata.c

src/cpp/client/create_channel.cc

src/csharp/Grpc.Core.Tests/Grpc.Core.Tests.csproj

src/csharp/Grpc.Core.Tests/MarshallingErrorsTest.cs

src/csharp/Grpc.Core.Tests/MetadataTest.cs

src/csharp/Grpc.Core.Tests/MockServiceHelper.cs

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

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

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

src/csharp/Grpc.Core/Marshaller.cs

src/csharp/Grpc.Core/Metadata.cs

src/csharp/Grpc.Examples.Tests/MathClientServerTests.cs

src/csharp/Grpc.HealthCheck.Tests/HealthClientServerTest.cs

src/csharp/Grpc.HealthCheck.Tests/HealthServiceImplTest.cs