Use math test to test generated code

package.json

src/compiler/node_generator.cc

src/node/.jshintignore

src/node/.jshintrc

src/node/test/math/math_grpc_pb.js

src/node/test/math/math_pb.js

src/node/test/math/math_server.js

src/node/test/math_client_test.js

templates/package.json.template