DDS — Ref-36 Entity_specialization_set_get_qos

The specification shows these operations as being abstract on the
base-class (Entity) and says that it will be overridden by each
specialization (Section 2.1.2.1.1.3). This is consistent with the PSM.

However, the get_listener/set_ listener operations are not mentioned
in the tables and text that that describe the DomainParticipant
(section 2.1.2.2.1.

Also for the specialized Entity classes, the operations are not
mantioned on the class table but do appear in the text that describes
the table. This applies to DomainParticipant (section 2.1.2.2.1),
Topic (section 2.1.2.3.2), Publisher (section 2.1.2.4.1), DataWriter
(section 2.1.2.4.2), Subscriber (section 2.1.2.5.2), and DataReader
(section 2.1.2.5.3.

**PROPOSAL**

In order to avoid ambiguity, the get_listener/set_listener operation
should appear explicitly in all the aforementioned sections.

see below