report status and target in update_main

+ add SECoP commands [WIP]
+ fix case 4 (error icon) in updateStatus (SEAWebClientCommunication.js)

base.py

@@ -88,10 +88,14 @@ class Client(HandlerBase):
         return dict(type='accept-console')
 
     def w_sendcommand(self, command):
+        result = None
         for node in self.nodes.values():
-            if node.handle_command(command):
+            result = node.handle_command(command)
+            if result is not None:
                 break
-        return dict(type='accept-command')
+        if isinstance(result, str):
+            return dict(type='accept-command', result=result)
+        return dict(type='accept-command')  # TODO: how to handle result is None?
 
     def info(self):
         return ["na"]