Rollup of changes from the latest import

BUILD

Makefile

binding.gyp

build.yaml

config.m4

gRPC.podspec

grpc.gemspec

include/grpc++/impl/codegen/client_context.h

include/grpc++/impl/codegen/create_auth_context.h

include/grpc++/impl/codegen/server_context.h

package.json

package.xml

src/core/lib/http/parser.c

src/core/lib/http/parser.h

src/core/lib/iomgr/udp_server.c

src/core/lib/surface/init.c

src/cpp/client/client_context.cc

src/cpp/server/server_context.cc

src/python/grpcio/grpc_core_dependencies.py

test/core/iomgr/udp_server_test.c