Classes have now names that begin with uppercase

This is more Pythonic and makes the code more readable.

Backwards compatibility is provided by giving an alias with the
previous name of the class.

It will not be broken until the next major release.

relational_gui/guihandler.py

@@ -18,7 +18,7 @@
 from PyQt5 import QtCore, QtWidgets, QtWidgets
 
 from relational import relation, parser, optimizer, rtypes
-from relational.maintenance import user_interface
+from relational.maintenance import UserInterface
 
 from relational_gui import about
 from relational_gui import survey
@@ -36,7 +36,7 @@ class relForm(QtWidgets.QMainWindow):
         self.selectedRelation = None
         self.ui = ui
         self.qcounter = 1  # Query counter
-        self.user_interface = user_interface()
+        self.user_interface = UserInterface()
 
         self.settings = QtCore.QSettings()