Implements #81 - webhook event backend (#1640)

* merge branch develop

* bugfix, signals for virtualization's class wasn't correctly defined

* updated webhooks for 2.4 and cleanup

* updated docs to cover changes to supervisor config

* review changes and further cleanup

* updated redis connection settings

* cleanup settings

netbox/dcim/apps.py

@@ -8,4 +8,10 @@ class DCIMConfig(AppConfig):
     verbose_name = "DCIM"
 
     def ready(self):
+
         import dcim.signals
+
+        # register webhook signals
+        from extras.webhooks import register_signals
+        from .models import Site, Rack, RackGroup, Device, Interface
+        register_signals([Site, Rack, Device, Interface, RackGroup])