Drop support for PySide

It's no longer developed and I'm moving to Qt5 which
is not supported

relational_gui/compatibility.py

@@ -19,45 +19,22 @@
 #
 # Module to unify the use of both pyqt and pyside
 
-
-try:
-    from PyQt4 import QtCore, QtGui
-    pyqt = True
-except:
-    from PySide import QtCore, QtGui
-    pyqt = False
-
+from PyQt4 import QtCore, QtGui
 
 def get_py_str(a):
     '''Returns a python string out of a QString'''
-    if pyqt:
-        return unicode(a.toUtf8(), 'utf-8')
-    return a  # Already a python string in PySide
-
+    return unicode(a.toUtf8(), 'utf-8')
 
 def set_utf8_text(component, text):
-    if not pyqt:
-        component.setText(text)
-    else:
-        component.setText(QtCore.QString.fromUtf8(text))
-
+    component.setText(QtCore.QString.fromUtf8(text))
 
 def get_filename(filename):
-    if pyqt:
-        return str(filename.toUtf8())
-    return filename[0]
-
+    return str(filename.toUtf8())
 
 def add_list_item(l, item):
-    if pyqt:
-        history_item = QtCore.QString()
-        history_item.append(item)
-        hitem = QtGui.QListWidgetItem(None, 0)
-        hitem.setText(history_item)
-        l.addItem(hitem)
-        l.setCurrentItem(hitem)
-    else:
-        hitem = QtGui.QListWidgetItem(None, 0)
-        hitem.setText(item)
-        l.addItem(hitem)
-        l.setCurrentItem(hitem)
+    history_item = QtCore.QString()
+    history_item.append(item)
+    hitem = QtGui.QListWidgetItem(None, 0)
+    hitem.setText(history_item)
+    l.addItem(hitem)
+    l.setCurrentItem(hitem)