Amend core to pass shell objects through

For 'handler' plugin definitions, also recognize
the 'console' exception to allow the plugin to pass
through to the shellserver infrastructure.

confluent_server/confluent/core.py

@@ -170,7 +170,7 @@ noderesources = {
     '_shell': {
         'session': PluginRoute({
             # For now, not configurable, wait until there's demand
-            'default': 'ssh',
+            'handler': 'ssh',
         })
     },
     'shell': {
@@ -530,6 +530,8 @@ def handle_node_request(configmanager, inputdata, operation,
             inputdata=inputdata)
         if isnoderange:
             return passvalue
+        elif isinstance(passvalue, console.Console):
+            return passvalue
         else:
             return stripnode(passvalue, nodes[0])
     elif 'pluginattrs' in plugroute: