
The PERSISTENT kind of the DURABILITY QoS policy configures the
publisher within a given domain to retain unsent data beyond the
lifetime of publishing process.

This test verifies properly functioning PERSISTENT DURABILITY support
in OpenDDS by performing the following actions:

1. Write data for a specific domain/topic/type through a DataWriter
   that has not been associated with a DataReader.  (No pub/sub match
   yet).
2. Allow the publisher process to end gracefully.
3. Restart the publisher program with a specific command line option
   to prevent it from writing the data again.
4. A subscription will then occur, after which the persistent data
   that was in the durability cache will be sent to the DataReader.
5. To test "service_cleanup_delay", a new DataWriter for a dummy topic
   will be created with the appropriate QoS settings.
