VisTrails Python 3 PyQt5

Porting to Python 3
-------------------
2to3 transforms most py2 strings to py3 strings with unicode support
use bytes in module hasher
use encode=unicode in elementtree.serialize
New ordering logic
 
Porting to PytQt5
-----------------
 
pyqt4topyqt5 issues:
  disconnect->connect!
  [0] inserted in getfilenamefromgui
  inserts signal [type] to connections
  Does not prefix opyqtSignal with "QtCore."
  Misses some connections?
 
qmatrix->qtransform (Backport?)
scene removed from constructors (qt5-fixes) (Backport?)
translate removed
qgraphicsitem.itemAt needs view transform
qmessagebox.information/... Custom buttons obsolete
 
new-style signals (pyqt4topyqt5 script leaves a lot of manual work) (Backport?)
 
pyqt5 uses cooperative multiple inheritance: (needs python 3)
    def __init__(**kwargs):
        super().__init__(**kwargs)