health checking protocol doc

Adds grpc.primary_user_agent key during stub creation

Exposes call#peer, channel#target

Eliminated some redundant checks in the Node interop client

Move Python protoc plugin tests to grpcio_test.

Set Python user-agent string.

Implement timeout interop test for Python.

Bounds checking for ops in call batch

Added Sandcastle project to generate C# docs

adding node, ruby, and php to cloud to prod interop tests.

Shutdown lb_policy when changing it

Added invocation of ./config

move auth property iterator declaration into auth_context.h

expose C core version string to C#

Upporting from 0.10 branch.

Improving unprotect doc.

C# Context API

Compression API, sending response headers and cleanup.

Fix gce detection

Fixes problem reading certificates file: They do come with non-ASCII chars (in comments)!

This would have caught the encoding problem with the default root
certificates.

Fix race condition in GRPCCall