This is a bugfix release.
- Deal with poll() POLLIN/POLLOUT before POLL[RD]HUP to correctly handle the case where a client sends data and immediately closes its socket.
- Fix memory leak with messages of QoS=2. Fixes bug #1064981.
- Fix potential thread synchronisation problem with outgoing packets in the Python module. Fixes bug #1064977.
- Fix “mosquitto_sub -l” incorrectly only sending one message per second.