Connections warned of badargs to ets:delete
when shutting the server down with open connections;
created noise while reviewing test results.

Added additional functional tests ensuring that
the pipelines empty and added some robustness
around the test server.

In preparation for work to ensure that request
load is balanced across connections, created failing
functional test to demonstrate current behavior.

New endpoint will never send back a response and can
be used for verifying timeouts and long running processes.

Moved receive of stop message to listening process
instead of connection and modified listener to come
up for air every once in a while to process.