Merge github.com:grpc/grpc into adjustable_window

BUILD

CMakeLists.txt

Makefile

binding.gyp

build.yaml

config.m4

gRPC-Core.podspec

grpc.gemspec

include/grpc++/create_channel_posix.h

include/grpc++/server.h

include/grpc/grpc_posix.h

package.xml

src/core/ext/client_config/client_channel.c

src/core/ext/client_config/lb_policy.c

src/core/ext/client_config/lb_policy.h

src/core/ext/client_config/subchannel.c

src/core/ext/client_config/subchannel.h

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

src/core/ext/lb_policy/pick_first/pick_first.c

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