This reverts commit d88e15ce.

Connectivity state FATAL_FAILURE doesn't exist; it is SHUTDOWN

Exposes a way to create channels with the CroNet stack

Use 2 clients for 8core setup as well

C# add support for multiple completion queues in GrpcThreadPool.

C# streaming api improvements

Use 2 clients for 32core throughput scenarios.

Make grpc_zookeeper.pc file generation consistent with other .pc files

Round robin notifier pollset

Add a Cython-level cancel-many-calls test

Avoid using unspecified keyword args where possible

Increase request_with_flags timeout deadline

Affinitize server call notification

Improve test debugability, fix race condition in set_initial_connect_string_test

Server was continuing to make requests for new calls forever, which were
starving out the shutdown sequence. Change order and win.