Merge pull request #4038 from dgquintas/grpclb_api

.gitmodules

BUILD

Makefile

binding.gyp

build.yaml

gRPC.podspec

grpc.gemspec

package.json

src/core/client_config/lb_policies/load_balancer_api.c

src/core/client_config/lb_policies/load_balancer_api.h

src/core/proto/grpc/lb/v0/load_balancer.pb.c

src/core/proto/grpc/lb/v0/load_balancer.pb.h

src/proto/grpc/lb/v0/load_balancer.options

src/proto/grpc/lb/v0/load_balancer.proto

src/python/grpcio/grpc_core_dependencies.py

templates/tools/run_tests/sources_and_headers.json.template

test/cpp/grpclb/grpclb_api_test.cc

third_party/nanopb

tools/codegen/core/gen_load_balancing_proto.sh

tools/distrib/check_nanopb_output.sh