Merge remote-tracking branch 'upstream/master' into stap

Makefile

gRPC.podspec

include/grpc++/channel_interface.h

include/grpc++/server.h

src/core/support/alloc.c

src/core/support/time_win32.c

src/core/surface/completion_queue.c

src/core/surface/completion_queue.h

src/core/surface/server.c

src/cpp/client/channel.h

src/cpp/server/server.cc

src/cpp/server/server_builder.cc

src/csharp/Grpc.Auth/.gitignore

src/csharp/Grpc.Auth/GoogleCredential.cs

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

src/csharp/Grpc.Auth/OAuth2InterceptorFactory.cs

src/csharp/Grpc.Auth/Properties/AssemblyInfo.cs

src/csharp/Grpc.Auth/app.config

src/csharp/Grpc.Auth/packages.config

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