Merge github.com:grpc/grpc into tis-but-thy-name

include/grpc/byte_buffer.h

src/core/iomgr/fd_posix.c

src/core/iomgr/pollset_multipoller_with_epoll.c

src/core/surface/byte_buffer.c

src/core/transport/chttp2/parsing.c

src/core/transport/chttp2_transport.c

src/ruby/ext/grpc/extconf.rb

test/core/surface/byte_buffer_reader_test.c

test/cpp/qps/server_async.cc