Merge github.com:grpc/grpc into lazy-parent

BUILD

CMakeLists.txt

Makefile

binding.gyp

build.yaml

config.m4

gRPC-Core.podspec

grpc.gemspec

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

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

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

include/grpc/impl/codegen/grpc_types.h

package.xml

src/compiler/cpp_generator.cc

src/compiler/cpp_generator.h

src/compiler/cpp_generator_helpers.h

src/compiler/cpp_plugin.cc

src/compiler/protobuf_plugin.h

src/compiler/python_generator.cc

src/compiler/python_generator.h