Merge github.com:google/grpc into async-api

src/node/examples/stock.proto

src/node/examples/stock_client.js

src/node/examples/stock_server.js

src/node/ext/byte_buffer.cc

src/node/ext/byte_buffer.h

src/node/ext/event.cc

src/node/src/server.js

src/node/test/client_server_test.js

src/php/lib/Grpc/ActiveCall.php

src/php/lib/Grpc/BaseStub.php

src/php/tests/interop/empty.php

src/php/tests/interop/interop_client.php

src/php/tests/interop/messages.php

src/php/tests/interop/test.php

tools/run_tests/jobset.py

tools/run_tests/run_tests.py