jp: jp asyncio port: /!\ this commit is huge. Jp is temporarily not working with `dbus` bridge /!\ This patch implements the port of jp to asyncio, so it is now correctly using the bridge asynchronously, and it can be used with bridges like `pb`. This also simplify the code, notably for things which were previously implemented with many callbacks (like pagination with RSM). During the process, some behaviours have been modified/fixed, in jp and backends, check diff for details.

--- a/twisted/plugins/sat_plugin.py	Wed Sep 25 08:53:38 2019 +0200
+++ b/twisted/plugins/sat_plugin.py	Wed Sep 25 08:56:41 2019 +0200
@@ -1,4 +1,4 @@
-#!/usr/bin/env python2
+#!/usr/bin/env python3
 # -*- coding: utf-8 -*-
 
 # SAT: a jabber client