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/sat/memory/disco.py	Wed Sep 25 08:53:38 2019 +0200
+++ b/sat/memory/disco.py	Wed Sep 25 08:56:41 2019 +0200
@@ -434,7 +434,7 @@
             extensions[form_type or ""] = fields
 
         defer.returnValue((
-            disco_infos.features,
+            [str(f) for f in disco_infos.features],
             [(cat, type_, name or "")
              for (cat, type_), name in list(disco_infos.identities.items())],
             extensions))