merge with head

BUILD

CMakeLists.txt

Makefile

binding.gyp

build.yaml

build_config.rb

cmake/msvc_static_runtime.cmake

composer.json

config.m4

doc/PROTOCOL-WEB.md

doc/command_line_tool.md

doc/environment_variables.md

doc/g_stands_for.md

examples/csharp/helloworld/generate_protos.bat

examples/php/composer.json

examples/php/greeter_client.php

examples/php/helloworld.pb.php

examples/php/helloworld.php

examples/php/helloworld_grpc_pb.php

examples/php/route_guide/route_guide.pb.php