Made Node tests support multiple versions and set the Node default version to 4 everywhere possible

Ruby docker files and config

Properly using our build.yaml source of truth to generate our list of public APIs.

Explicitly cast constant value to gpr_atm

Node tools: use the right extension for running protoc on Windows

C# cleanup client-side call RECV_STATUS_ON_CLIENT internals

Stress test fixes

Always build the grpc library when building the ruby extension.

Add C# stress client to the test framework

Disable fail fast for qps driver

Create Python stress test

Fix bug where max_frame_size was ignored

Created grpc-tools ruby gem for distributing protoc and the plugin

Reverted 'Rewrite Node greeter example to use generated code'

Fix call state

Also add corpus entries that helped diagnose this bug

Fix a case whereby we leak a winsocket if we fail to connect

Ensure minimum size of alt stack (to please vtune)

- properly fail a Read() on a stream if we fail to parse a protobuf
- fix an ordering problem with the chttp2 transport global lock, whereby
  a sequence of two operations could be swapped - this resulted in
  slices being returned to the upper layers in the wrong order,
  corrupting data