Firewall rule to accept communication between HA nodes created
Firewall rule is now created even if firewall is not enabled

 - Also some reordering and debug messages
When deleting HA network object, force the removal of object members

 - The true core fix still pending. When done, we should remove those lines
Network object member has correct values
Added defensive code to avoid undef clusterStatus behaviour
Improved management of HA network object members

 - When creating the cluster, if the network object already exists, existing
   members are removed, and added the proper one.
 - This way, every future host joining the cluster will be added easier
Firewall and Objects modules need to be saved after bootstrap

 - Firewall is saved before the HA bootstrap, so we need to save its changes
Firewall rule is only created if it does not already exist
Added defensive code when interacting with objects and firewall modules
Defensive code to avoid UI crash
When joining or abandoning the cluster, HA network object is updated

 * Also some reordering and refactoring
Firewall management improvement
Allow network proxy which is listening on localhost
Fixed error which skipped the execution of _preSetConf
When cluster node IP is changed, cluster conf changes accordingly
Small refactor - Fixing an unsaved objects module state
Merge branch '3.4' into mjulian/ha-firewall-integration
Update changelogs
Fixing unit tests
Changelogs entries improved