misc python3 updates:

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

gui/qt/main_window.py

@@ -38,7 +38,7 @@ from PyQt4.QtGui import *
 from PyQt4.QtCore import *
 import PyQt4.QtCore as QtCore
 
-from lib.util import bh2u, bfh
+from electrum.util import bh2u, bfh
 from . import icons_rc
 
 from electrum import keystore