fix figures not showing with mix of upper and lower case variables

Before naming variables with lower and upper case could cause them to be sorted in wrong order since Python sorts by default first upper case strings (AB...ab...), and then lower case strings, whereas order in JavaScript is  aAbB...

ifigures/interact.py

@@ -226,7 +226,8 @@ def _output_html(self):
         defaults = tuple([widget.default for widget in self.widgets.values()])
 
         #Now reorder alphabetically by names so divnames match javascript
-        names,values,defaults = zip(*sorted(zip(names,values,defaults)))
+        names,values,defaults = zip(*sorted(zip(names,values,defaults),
+                                            key=lambda tup: tup[0].lower()))
 
         results = [self.function(**dict(zip(names, vals)))
                    for vals in itertools.product(*values)]