Merge branch 'master' of https://github.com/grpc/grpc into ct-you-complete-me

doc/connectivity-semantics-and-api.md

include/grpc/grpc.h

include/grpc/support/slice.h

src/compiler/cpp_generator.cc

src/core/support/log_win32.c

src/core/transport/stream_op.h

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

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

...arp/Grpc.Core.Tests/Internal/ChannelArgsSafeHandleTest.cs

src/csharp/Grpc.Core/Channel.cs

src/csharp/Grpc.Core/ChannelOptions.cs

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

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

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

src/csharp/Grpc.Core/Server.cs

src/csharp/Grpc.IntegrationTesting/InteropClient.cs

...csharp/Grpc.IntegrationTesting/InteropClientServerTest.cs

src/csharp/ext/grpc_csharp_ext.c

src/php/README.md

src/php/bin/run_gen_code_test.sh