New VOID middleware implementation

Measuring any middleware implementation using APEX performance could lead to some abnormal data (i.e.latency peaks) due to the operative system rescheduling and priorities. In order to be able to determine if an abnormal data could occur because of the OS or because a specific middleware implementation, a new VOID implementation has been implemented. This implementation does not use an internal middleware, but passes the data (id + time) directly from the publisher to the subscriber. This allows to see if a possible peak in a data (in latency, for example) is due to the middleware execution or to the OS.

This is a Proof of Concept more than a final implementation. Several modifications and improvements could be done in order to correctly test different configurations.

Signed-off-by: jparisu javierparis@eprosima.com