misc python3 updates:

- use jsonrpclib-pelix
 - update the kivy gui
 - update plugins

gui/kivy/uix/dialogs/wallets.py

@@ -1,13 +1,14 @@
+import os
+
 from kivy.app import App
 from kivy.factory import Factory
 from kivy.properties import ObjectProperty
 from kivy.lang import Builder
 
-from electrum_gui.kivy.i18n import _
 from electrum.util import base_units
 
-import os
-from label_dialog import LabelDialog
+from ...i18n import _
+from .label_dialog import LabelDialog
 
 Builder.load_string('''
 #:import os os