Closes #1674. Thanks to amigian74.

This prevents the session expiry being extended on SIGHUP.

Closes #1521. Thanks to Christoph Krey.

Closes #1664. Thanks to Leon Kiefer.

Issue #1653.

Rather than letting the bridge fail later.

Issue #1635. Thanks to pokerazor.

Issue #1641.

Issue #1629. Thanks to radcrabs.

Plus add missing header.

This patch changes the behavior of how mosquitto is starting using
systemd.

Currently it is starting only when the network is online, meaning that the
network is configured to a routable IP address.

With this patch, mosquitto is starting when the network is offline, does
not need to be configured. This is needed because the MQTT broker might
be used as an internal message bus which does not need the network to be
online.

Signed-off-by: Stavros Vagionitis <stavros.vagionitis@jci.com>

Since all resources are ready, do not need lookup again.

Signed-off-by: Michael Liu <michael.liu.point@gmail.com>

WebSocket context may lost since db->ll_for_free = NULL; operation on the bottom of context__free_disused() function.

Signed-off-by: Michael Liu <michael.liu.point@gmail.com>

Closes #1614. Thanks to Christoph Krey.

Closes #1622.

It was not returning MOSQ_ERR_INVAL if the topic contains a wildcard.

Closes #1589. Thanks to mdelete.

Closes #1519. Thanks to Christoph Krey.

Default behaviour for v5 clients using `-c` is now to use infinite length
sessions, as with v3 clients.

Closes #1546. Thanks to Kiran Pradeep.