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

examples/php/README.md

src/core/compression/algorithm.c

src/core/surface/byte_buffer.c

src/core/surface/call.c

src/csharp/Grpc.Auth/AuthInterceptors.cs

src/csharp/Grpc.Auth/Grpc.Auth.csproj

src/csharp/Grpc.Auth/GrpcCredentials.cs

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

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

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

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

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

src/csharp/Grpc.Core.Tests/Internal/AsyncCallTest.cs

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

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

src/csharp/Grpc.Core/CallCredentials.cs

src/csharp/Grpc.Core/CallOptions.cs

src/csharp/Grpc.Core/Channel.cs

src/csharp/Grpc.Core/ChannelCredentials.cs

src/csharp/Grpc.Core/ClientBase.cs