Merge github.com:grpc/grpc into i-want-to-wait-free

.gitignore

Makefile

doc/connection-backoff.md

include/grpc++/impl/call.h

include/grpc++/server_context.h

include/grpc++/stream.h

include/grpc/support/port_platform.h

src/compiler/objective_c_generator.cc

src/core/httpcli/httpcli.c

src/core/iomgr/socket_windows.c

src/core/iomgr/tcp_server_windows.c

src/core/security/secure_transport_setup.c

src/core/security/secure_transport_setup.h

src/core/security/server_secure_chttp2.c

src/core/support/stack_lockfree.c

src/core/support/stack_lockfree.h

src/core/surface/secure_channel_create.c

src/core/transport/chttp2/frame_data.c

src/cpp/server/async_server_context.cc

src/cpp/server/server_context.cc