streaming (sync and async) APIs

Add the option of adding a non-listening server completion queue. This makes writing certain test cases (like hybrid_end2end tests) easier

There is a comment above IsCancelled that says when it is ok to use this.

In some cases, the prototype argument order was different
than the declaration order.

Based on a patch from Sam Leffler.

Original PR #3074 by @dgquintas

Minor fixes to previously existing docs.

Use it to validate that arithmetic on time types makes even some vague
kind of sense.

Move completion queue binding for new requests to the new request
request time, not server instantiation time.

Add a GrpcLibrary class to wrap grpc_init and grpc_shutdown and convert all the tests to init/shutdown free.