Add a health checker service implementation.

Replaced remaining references to 'listen' with 'start'

Adds the remaining ruby interop tests

Grpc ruby add timeout interop test

Fixing zookeeper's installation.

- adds the code-generated health service classes to the pb along with
  a README explaining how to regenerate the generated code

- adds an implementation of the Health Checker Service along with unit
  tests and an integration test

Also:
- adds a pb folder
  : in a follow-up PR, all ruby pbs + generated code will be moved to it

Zookeeper name resolver

Add ::grpc:: prefix

Dont generate package directories in C# protoc plugin output

Give make a long timeout, tests a small one, and interop a slightly longer one

Wrap connectivity API, expose it to client as waitForReady

Corrects some other issues

- fixes status return when calls fail by always returning the status

- resolves bidi_call client's failure to return an exception on bad
  status by swapping the wait for status to the read thread

  * this also improves the cancel_after_first_response test

Also

- adds a unit test that verifies that a bidi call will time out.

Add UDP server to gRPC.

Renamed "none" as "identity" for the no-op compression algorithm

- timeout has been a default arg till now

- this switches it to a keyword arg with the same behavior

- in addition, it adds deadline as distinct keyword arg, allowing users
  the choice of the idiomatic(timeout) or the aligned(deadline)

Recreating grpc_test_util_unsecure's template.

Reducing JUnit's report size.

Use a sync service to handle requests to unknown services

Adding reserved arguments and pointers in the API to ensure stability.

Conflicts:
	Makefile

use proto3 syntax in c++ test protos