Add well known protos to Node and Ruby tools packages

Fix namespace package usage

Load default roots.pem in PHP via grpc_set_ssl_roots_override_callback

Delete tests of dead pre-GA code

Fix secure channel construction

Added third_party/protobuf/src to protoc's include path

Adjust cpu_cost of some tests to better reflect reality

Reduce cost of some heavyweight tests

Unifying error handling within core

Make C++ compile and run under gcc-4.4

Idempotent endpoint shutdown

PHP: implement custom_metadata interop, status_code_and_message, unimplemented_method tests

Update third_party/protobuf to v3.0.0-beta-3.2