plugin XEP-0085: Chat State Notifications

- new "options" parameter to send chat states
    - plugin command export: messages without body are now delivered (since all the chat states other than "active" need them)

src/plugins/plugin_exp_command_export.py

@@ -107,8 +107,9 @@ class CommandExport(object):
         try:
             body = [e for e in message.elements() if e.name == 'body'][0]
         except IndexError:
-            warning("Received message without body")
-            return False
+            # do not block message without body (chat state notification...)
+            warning("No body element found in message, following normal behaviour")
+            return True
 
         mess_data = unicode(body) + '\n'