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.

When building the native extension make -j can absorb all available
resources on a system.  Implement "reasonable" limits on the number
of compiling jobs when the number of processors can be detected and
use a conservative count when ruby version does not provide detection.

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

client now conforms to spec. See
https://github.com/grpc/grpc/blob/master/doc/negative-http2-interop-test-descriptions.md