Merge github.com:grpc/grpc into direct-calls

BUILD

CMakeLists.txt

Makefile

binding.gyp

build.yaml

config.m4

gRPC-Core.podspec

grpc.gemspec

package.xml

src/core/ext/lb_policy/grpclb/grpclb.c

src/core/ext/lb_policy/round_robin/round_robin.c

src/core/lib/iomgr/ev_epoll_linux.c

src/core/lib/iomgr/ev_poll_posix.c

src/core/lib/iomgr/ev_poll_posix.h

src/core/lib/iomgr/ev_posix.c

src/core/lib/iomgr/wakeup_fd_cv.c

src/core/lib/iomgr/wakeup_fd_cv.h

src/core/lib/iomgr/wakeup_fd_pipe.c

src/core/lib/iomgr/wakeup_fd_posix.c

src/core/lib/iomgr/wakeup_fd_posix.h