Update RELEASE_NOTES and CHANGES.html

CHANGES.html

@@ -77,6 +77,12 @@ us a note on ns-developers mailing list.</p>
 <li>Nix-Vector routing supports topologies with multiple WiFi networks using the same WiFi channel object.</li>
 <li>ConfigStore does not save anymore OBSOLETE Attributes.</li>
 <li>The <b>Ipv4L3Protocol</b> Duplicate detection now accounts for transmitted packets, so a transmitting multicast node will not forward its own packets.</li>
+<li>Wi-Fi: A-MSDU aggregation now implies that constituent MSDUs are immediately dequeued
+from the EDCA queue and replaced by an MPDU containing the A-MSDU. Thus, aggregating N
+MSDUs triggers N dequeue operations and 1 enqueue operation on the EDCA queue.</li>
+<li>Wi-Fi: MPDUs being passed to the PHY layer for transmission are not dequeued, but
+are kept in the EDCA queue until they are acknowledged or discarded. Consequently, the
+BlockAckManager retransmit queue has been removed.</li>
 </ul>
 
 <hr>

RELEASE_NOTES

@@ -40,6 +40,7 @@ New user-visible features
 - (wifi) Add support for 11ax MU EDCA Parameter Set.
 - (mobility) Add GroupMobilityHelper and demonstrate its use with a new program that configures the Reference Point Group Mobility model for a number of nodes.
 - (buildings) Add example program demonstrating group mobility with the buildings-aware random walk mobility model, and a script to animate the group motion.
+- (wifi) MPDUs discarded because they became "old" (from the Block Ack agreement point of view) are now traced using the DroppedMpdu trace source of RegularWifiMac and with the WIFI_MAC_DROP_QOS_OLD_PACKET reason.
 
 Bugs fixed
 ----------