state (including channels)

alarm_test, tcp_posix, fd_posix, pollset_posix, credentials, call,
channel, server, child_channel

This test will become a suite over coming weeks.
Spin up a server, and send some illegal data to it, and probe that the correct behavior occurs.

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

Simplify grpc_event into something that can be non-heap allocated.
Deprecate grpc_event_finish.
Remove grpc_op_error - use an int as this is more idiomatic C style.