Merge branch 'stable' into release-2.4

Conflicts:
	app/controllers/call_flows_controller.rb
	app/controllers/call_logs_controller.rb
	app/models/call_log.rb
	broker/src/util.erl
	config/deploy.rb
Fix test
Fetch alto_guisso from GitHub
Add call duration to the status callback
Merge from release-2.4 branch