Expose AuthContext in C#

Use gpr_subprocess in fling_stream_test

Upmerge of 1.1.x to master.

Use grpc_build_system.bzl in other projects

Update PROTOCOL-WEB.md

replaced protobuf tag

Add a slice type that shares a refcount with a transport stream

Disable node_protobuf_async_unary_qps_unconstrained benchmark test

Eliminate cancellation if we never sent an op down

Avoid using oversized frames

Lint progress.

Add fixtures for call creation benchmarks

Add licenses() in BUILD files

Remove text-base64 C-T. Will revisit if we ever need support non-default (base64) encoding.

Added //external to grpc deps in case where grpc_build_system.bzl is
imported in a project that is using grpc as a dependency.

Lint fixes.

Remove grpc.beta._connectivity_channel.

In _server.py start_server_batch_result is removed because
start_server_batch can only ever fail as a result of a programming
defect in gRPC Python and not the application. This differs from some
analogous-appearing points in _channel.py where the result of
start_client_batch is checked because at those points it is possible
for a failure to indicate a programming defect on the part of the
application.

Add sleep(1) to Python negative http2 client

re-enable ruby tests on mac

This should have been removed in, and has done anything but fail on
import since, 4d425522.