Merge remote-tracking branch 'ctiller-repo/we-dont-need-no-backup' into poller2

include/grpc/grpc.h

src/core/iomgr/pollset_multipoller_with_epoll.c

src/core/iomgr/pollset_multipoller_with_poll_posix.c

src/core/iomgr/pollset_posix.c

src/core/surface/call.c

src/core/surface/call.h

src/core/surface/completion_queue.c

src/core/surface/completion_queue.h

src/core/surface/server.c

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/AsyncCallServer.cs

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

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

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

src/csharp/Grpc.Core/Server.cs